REFRIGERATING    ENGINEERS'    POCKET   MANUAL 


'EFRIGERATING    ENGINEERS'    POCKET   MANUAL. 


"Vesterdahl" 

Refrigerating 

and  Ice   Making 

Machinery 


Pipe  Work  in 
all  its  branches 


Steam  Driven  Machine 


Ammonia,  Chloride 
of  Calcium,  Am- 
monia -  Oil  an  d 
General  Supplies 


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REFRIGERATING    ENGINEERS'    POCKET   MANUAL. 


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REFRIGERATING    ENGINEERS1    POCKET    MANUAL. 


REFRIGERATING    ENGINEERS'    POCKET   MANUAL. 

IF     IT'S    ANYTHING     CONNECTED     WITH     COLD 
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REFRIGERATING    ENGINEERS'    POCKET    MANUAL. 


York    Manufacturing 
Company 

YORK,  PA. 

We  manufacture    all    the  machinery  and  parts  needed  to  equip 

A  COMPLETE  ICE 
OR  REFRIGERATING  PLANT 

Single  Acting  Machines,  Double  Acting 
Machines,  Absorption  Machines,  Con- 
densers, Tanks,  Cans,  Coolers,  Piping, 
Boilers  and  Ammonia  Fittings  of  all  kinds. 

We  employ   over    1250   men   in    the    manufacture   of   Ice    and 
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THE 
REFRIGERATING  ENGINEER'S 

POCKET  MANUAL 


An  Indispensable  Companion  for  Every  Engineer  and  Student 
Interested  in  Mechanical  Refrigeration 


By  OSWALD  GUETH,  M.  E. 

Member  Am.  Soc'y  Refr.  Eng'rs 


NEW  YORK; 
1908 


Copyright,   1908 
By   OSWALD  GTJE3TH 


-••"*'•»•    *  • «  * 

"•  •       * » • 


PREFACE 


When  the  author  decided  to  christen  his  book  a  "Pocket 
Manual"  he  was  moved  to  do  so  by  the  words  of  Kent,  that 
"every  engineer  should  make  his  own  pocketbook."  Un- 
fortunately not  every  engineer  has  the  opportunity  or  ability 
to  gather  useful  information  without  paying  dearly  for  it. 

This  "long-felt  want"  is  intended  to  be  filled  by  the  "Pocket 
Manual,"  a  digest  of  the  rules  and  data  of  every  branch  of 
mechanical  refrigeration,  embodying  the  opinions  of  the  fore- 
most men  in  the  field,  together  with  the  practical  experience 
of  the  author,  a  receptacle  for  further  research  and  enlarge- 
ment, a  pocketbook  in  the  very  sense  of  the  word,  which  the 
author  trusts  will  soon  find  its  way  into  the  pocket  of  every 
progressive  refrigerating  engineer. 


CONTENTS 


Part  I. — Principles  and  Properties. 


THERMODYNAMICS    

Definitions     

Laws   

Expansion  and  Compression. 


Page. 
1 
1 
1 
2 


Specific   Heat,    tables 2 

Thermometer  Scales    3 

WATER     4 

Properties   4 

Tests  for  Purity  4 

AIR    5 

Humidity    5 


Tage. 

Equation  of  pipes    6 

Standard  Table  of  pipes 6 

REFRIGERATING   MEDIA    ...  7 

Boiling  points    7 

Latent  heat   8 

Ammonia  7 

Aqua  ammonia    9 

Carbonic    Acid,    etc 11 

BRINE     12 

Chroride  of  Sodium 12 

Chloride  of  Calcium 13 


Part  II. — Refrigerating  Machinery. 


HISTORY— Freezing    Mixtures.     15 


COLD  AIR  MACHINES 

16 

VACUUM  MACHINES 

19 

COMP 
Ref 

ABSORPTION    MACHINES    .. 
Management   

.     22 
24 

Hor 
Ecoi 

Economy    

25 

Dry 

COMPRESSION  MACHINES    . 
Ether  Machines    

28 
28 

COND 
Con 

Sulphur  Dioxide  Machines... 

28 

Var 

Carbonic  Acid  Machines 29 

Ammonia  Machines  31 

SOR  33 

Refrig.  Capacity  33 

sver  34 

Economy 35 

Dry  vs.  Wet  Compression ....  37 

SR  39 

Condenser  Surface  39 

Amount  of  Cooling  Water....  39 

Various  Types  of  Condensers.  40 


Part  III. — Applications  of  Mechanical  Refrigeration, 


INSULATION    44 

Fireproof  Construction    44 

Tank  Insulation    47 

Heat    Transmission    through 

pipes    48 

Heat    Transmission    through 

various  Insulations   48 

Relative  Value  of    Non-Con- 
ductors     49 

Details  of  Insulation 49 

GENERAL  COLD  STORAGE...  54 

Cold  Storage  Temperatures. .  .  54 

Refrigeration  Required   54 


Piping    56 

Brine  Cooling  System 58 

Forced  Air  Circulation 58 

BREWERY    REFRIGERATION  60 

Beer  Cooler    60 

Attemporators   62 

Piping  of  Cellars 62 

Brine  vs.  Direct  Expansion..  64 

PACKING    HOUSE    REFRIG- 
ERATION       66 

Refrigeration  Required 67 

Piping    67 


CONTENTS. 


Page. 

CAN  ICE  PLANTS 68 

Time    of    Freezing G8 

Freezing  Tanks   68 

Ice  Storage   70 

Cost    of    Ice 70 

Coal     Consumption 71 

Water  Consumption    71 

DISTILLING  APPARATUS   ...  72 

Grease  Separator 72 


Steam   Condenser    

Skimmer  and  Reboiler.... 

Water  Regulator    

Condensed  Water  Cooler . . 

Filter    

Storage  Tank  


Page. 

Evaporator  System  87 

Multiple    Effect    Evaporators.     88 

Space  Required  for  Can  Ice 
Plants    90 

PLATE   ICE   PLANTS 99 

Direct  Expansion  Plate 99 

Brine   Coil   Plate 100 

American   Linde   Plate 101 

Plate  Ice  vs.  Can  Ice 103 

Space    Required    104 

PIPE  LINE  REFRIGERATION  107 

AUTOMATIC     REFRIGERAT- 
ING MACHINES    109 


Part  IV. — Operation  of  Compression  Plant. 


ERECTION     AND     MANAGE- 
MENT       Ill 

Foundation    Ill 

Testing   Plant    Ill 

Charging  Plant   112 

Pumping  Out  Connections....   112 


EFFICIENCY  TEST    116 

Indicator  Diagram   116 

Record  of   a   Test    117 

Rules     for     Testing     Refrig. 
Machines    ...  , .   118 


Part  V.— The  Steam  Plant. 


STEAM  ENGINES   123 

Horse   Power   123 

Valve  Setting  of  Corliss  En- 
gine      124 

Steam    Engine    Indicator 126 

Taking    Care   of   Corliss    En- 
gine       128 

Air  Pumps    128 

Standard        Corliss     Engines 

(table)    129 

STEAM  BOILERS   130 

Horse  Power    130 

Heating  Surface   131 

Standard    Tubular    Boilers...  131 

Fuel    131 

Size   of   Chimney    132 

Water   for  Feeding   Boilers..  132 

Feed    Water    Heaters...          .  133 


Steam    134 

Care  of  Boilers  136 

Rules    for    Conducting    Boiler 

Test 137 

PUMPS     143 

Pressure  and  Head  143 

Horse  Power    144 

Capacity    144 

Efficiency     145 

Directions      for      Connecting 

and  Running  Pumps   146 

Duty  Trials  of  Pumping  En- 
gines     147 

MISCELLANEOUS   151 

Belt   Transmission    151 

Electrical      and      Mechanical 

Units   152 

Cooling  Towers    153 


Topical  Index. 


Page. 

Absolute  Zero    3 

Absorption  Machines   22 

Air,   Properties   5 

Circulation     58 

Pump    128 

Humidity   5 

Ammonia,  Anhydrous   7 

Liquor    9 

Refrigerating  Effect    33 

Attemporators    62 

Automatic     Refrigerating    Ma- 
chines      109 

B. 

Beer    Coolers     60 

Belt    Transmission     151 

Brewery  Refrigeration  60 

Brine,   Properties  12 

System   58 

By-Pass   112 

C. 

Can  Ice  Plants 68 

Capacity     of    Compressor 33 

Ice   plant    68 

Condensed    Water    Cooler 81 

Carbonic    Acid,    Properties 11 

Machines    29 

Cold    Air   Machines 16 

Cold  Storage    54 

Compression  Machines   28 

Compressor   33 

Condenser,  Ammonia  39 

Steam    72 

Cooling   Towers    153 

Coke  Filter  82 

D. 

Distilling  Apparatus  72 

Dry  TS.   Wet  Compression   37 

E. 

Efficiency  Test 116 

Erection    of    Plant Ill 

Equation  of  Pipes 6 

Ether  Machines   28 

Ethyl  Chloride  Machines 11 

Evaporator  System  87 

Economy    of    Absorption    Ma- 
chine    25 

Compression  Machine    35 

F. 

Feed  Water  Heater 133 

Filter    ; 82 

Forced  Air  Circulation 58 

Freezing  Mixtures    15 

Freezing  Tanks   68 

Foundations     Ill 

Fuel    131 


Grease  Separator 


G. 


72 


H. 


Heat     Transmission     Through 

Pipes     48 

Horse  Power  of  Compressor 34 

Steam  Engine    123 

Steam  Boiler   130 

Pump    144 

Shafting    151 

Humidity  of  Air 5 


I. 


Page. 


Ice  Cans    68 

Storage    70 

Thickness    68 

Indicator     Diagram     of     Com- 
pressor     H6 

Steam    Engine    126 

Insulation   44 

L. 

Latent   Heat    8 

M. 
Management  of — 

Absorption  Machine  24 

Compression  Machine   Ill 

Mean  Effective  Pressure  of — 

Compressor     116 

Steam   Engine    123 

P. 

Packinghouse  Refrigeration    ...  66 

Pipe    Standard   Table 6 

Pipe   Line   Refrigeration 107 

Plate  Ice  Plants  99 

Pumps     143 

Pictet  Fluid  11 

R. 

Reboiler    76 

Refrigeration   required    for — 

Breweries     60 

General    Cold    Storage 54 

Packinghouses     67 

Refrigerating  Media   7 

Capacity  of  Compressor 33 

Effect  of  Ammonia    33 

S. 
Specific  Heat  of — 

Various  Solids   2 

Cold    Storage    Goods 3 

Steam,    Properties    135 

Engines    123 

Boilers   130 

Condensers  72 

Skimmer  and  Reboiler  76 

Storage  Tank   83 

Sulphur  Dioxide  Machines 28 

T. 

Thermometer  Scales    3 

Thermodynamic  Laws   1 

Temperatures,  Cold  Storage 54 

Ice   Storage    70 

Testing,   Ammonia    8 

Water  "4 

Refrigerating  Machines    116 

Steam  Boilers    137 

Pumps    147 

TT. 

Units,    Electrical   and  Mechan- 
ical      152 

British  Thermal   1 

V. 

Vacuum    Machines 19 

Valve  Setting  of  Engine 124 

W. 

Water,    Properties    4 

Tests    4 

Boiler  Feed    132 

Regulator    80 

Wet  and  Dry  Compression 37 


PART   I— PRINCIPLES   AND  PROPERTIES 


Thermodynamics 

A  "British  Thermal  Unit" 

Is    the    heat    necessary    to    raise    one    pound    of    water    1°    F.    at 

temperature  of  greatest  density  which  is  39°  to  40°. 

In  mechanical  energy  or  work,  a  heat  unit  is  equivalent  to  rais- 
ing a  weight  of  one  pound  to  a  height  of  778  feet  or,  778  pounds 
to  a  height  of  one  foot.  The  mechanical  equivalent  of  heat  then  is 
778  foot-pounds. 

"Sensible  Heat." 

is  that  which  is  measured  by  a  thermometer  or  is  apparent  in 
change  of  temperature,  and  for  ordinary  calculation  each  degree 
that  water  is  heated  may  be  considered  one  unit  of  heat  for  each 
pound  of  water,  so<  that  the  weight  of  water  multiplied  by  the 
increase  of  temperature  equals  the  heat  units  absorbed. 

"Latent  Heat." 

is  that  which  is  absorbed  by  a  body  in  causing  change  of  structure 
without  increase  of  temperature.  One  pound  of  Ice  with  a  tempera- 
ture of  32°,  when  melted  will  give  one  pound  of  water  at  a  tem- 
perature of  32°,  but  to  melt  the  ice  heat  is  absorbed  ;  this  heat  does 
not  increase  the  temperature,  although  142  units  are  necessary. 
Water  boils  at  a  temperature  of  212°.  Each  pound  of  water  re- 
quires 966  units  of  heat  to  convert  it  into  steam  ;  the  212°  is  sensible 
heat,  the  966°  latent  heat,  these  added  together  give  the  total  heat 
of  steam  when,  water  is  evaporated  in  an  open  vessel  =  1178  units 
sufficient  to  heat  1178  pounds  of  water  1°. 

When  water  is  evaporated1  under  pressure  the  sensible  heat  in- 
creases while  the  latent  heat  decreases.  At  100  pounds  pressure 
the  boiling  water  has  a  temperature  of  338°,  the  latent  heat  is 
879,  the  total  heat  1217  units. 

"Specific  Heat." 

The  ratio  of  heat  required  to  raise  the  temperature  of  a  given 
substance  one  degree  to  that  required  to  raise  the  temperature  of 
the  same  weight  of  water  one  degree  (from  39.1°  Fahr.,  the  tem- 
perature of  maximum  density)  is  called  the  specific  heat  of  the 
substance. 

Thermodynamic  Laws. 

The  following  laws  relating  to  a  perfect  gas  may  be  safely  ap- 
plied to  all  gases  : 

A.  The  pressure  varies  inversely  as  the  volume  when  the  tem- 
perature is  constant  (Boyle). 

V         P' 

—   =  —  VP  —  Constant. 

V         P 

B.  The    pressure    varies    directly    as    the    absolute    temperature 
when   the  volume  is   constant    (Charles). 

P       T  +  461 

P'        T'  -f  461 

C.  The  volume  varies  directly  as  the  absolute  temperature  when 
the   pressure   is    constant. 

V        T   +  461 

V  =  T  +  461 


2  :       •  ,.    THERMODYNAMICS. 

D.  The  product  of  the  pressure  and  volume  varies  directly  aa 
the  absolute  temperature. 

p  y  /«  T    +  461  P        V    (T    +  461) 

P'  V'        T'  +  461  '          P'        V      (T  +  461) 

Taking  the  volume  of  one  pound  of  air  at  14.7  Ibs.  abs    press 
and  at  32°  =  12,387  cb    ft.,   absolute  temp.  =  32°  +  461  =  493°. 
12.387  X  14.7  1 

-  =  .36935   or  ----- 
493  2,7074 

This  fraction  is  a  constant  "a"  which  when  multiplied  by  the 
weight  and  temperature  of  the  gas,  and  divided  by  the  pressure 
will  give  the  volume. 

VP  -  a   (T  +  461) 
Expansion  and  Compression. 

Under  the  first  law  of  thermodynamics  V  P  is  a  constant,  that 
is,  the  curve  which  represents  the  variation  of  the  pressure  through- 
out the  stroke  of  a  piston,  is  a  hyperbola  and  the  operation  Is 
termed  "isothermal"  compression  or  expansion,  the  curve  of  equal 
temperatures. 

Under  the  fourth  rule  D  we  have  to  add  to  the  pressures  at 
every  successive  stage  during  compression  the  heat  units  which  are 
equivalent  to  such  work,  and  we  obtain  instead  an  isothermal 
compression  an  "adiabatic"  compression,  and  instead  of  V  P  being 
constant,  V  P  is  raised  to  such  power  as  is  appropriate  to  the  par- 
ticular gas  in  question.  In  the  case  of  ammonia  the  pressure 
varies  inversely  as  the  volume  raised  to  the  1.298  power 
P'  v  1-298 


(See  tables  I   and  II,   page  117,  by  Voorheis.) 

SPECIFIC  HEAT   OF   VARIOUS   SUBSTANCES. 

SOLIDS. 


Antimony 0.0508 

Copper 0. 09pl 

Gold  - 0.0374 

Wrought  iron 0.1138 

Glass  0.1937 

Cast  iron 0.1398 

Lead 0.0314 

Platinum 0.0324 

Silver O.OaTO 

Tiu  ..  ..  0.0502 


Steel  (soft)... 0.1165 

Sieel  (hard) 01175 

Zinc ,  00956 

Brass 0.0939 

Ice 0-5040 

Sulphur 0.203ft 

C'harcoal 0.2410 

Alumina 0.1970 

Phosphorus , 0.1887 


LIQUIDS. 


Water 1.0000 

Lead  (melted): 0.0402 

Sulphur    "      0.2340 

Bismuth    "      00308 

Tin  " 0.0637 

Sulphuric  acid 0.3350 


Mercury 

Alcohol  (absolute) 0.7000 

Fusel  oil 0.5540 

Benzine. 0.4500 

Ether .».. 0.5034 


GASES. 
Constant  Pressure.    Constant  Volume. 

Air 0.2$751  0.16847 

Oxygen 0.21?51  0.15507 

Hydrogen 3.40900  2.41226 

Niirogen 0.24380  0.17273 

Superheated  steam 0.4805  0.346 

Carbonic  acid 0217  0.1535 

Olefiant  Gas  (CH2) 0.404  0  173 

Carbonic  oxide 0.2479  01758 

Ammonia 0503  0.299 

Ether     0.4797  0.3411 

Alcohol 0.4534  0.3200 

Acetic  acid „  0.4125  

Chloroform.  .....  ..  0.1567 


SPECIFIC   HEAT   OF   COLD   STORAGE   GOODS. 


Composition. 

3     c  « 

||| 

Composition. 

a  <=••»• 
x  «'«•? 

s  j'w'i 

it! 

s-o'jj- 

5  S  r 

s-e's- 

•5  ITS  3    EJJs 

Water. 

Solids. 

8.   £x 

!^ 

*** 

Water.  Solids.  «  '"^.jj 

}I]IJ;1 

Beef,  lean 

72.00 

28.00 

0.77 

0.41 

102 

Cream  .  .  . 

59.25j30.75   0.68 

0.38 

84 

Heef  ,  fat.  . 

51.  OC 

49.00 

.60 

.34 

72 

Milk.     .. 

87.5012.50 

.90 

.47 

124 

Veal  

63.00 

37.00 

.70 

.39 

90 

Oysters... 

80.3819.02 

.84 

.44 

114 

Pork,  fat  . 

39.00 

61.00 

.51 

.30 

55 

Whitefish, 

78.0022.00 

.82 

.43 

111 

Eggs  

70.00,30.00 

.76 

.40 

100 

Eels  

62.0737.93 

.69* 

.38 

88 

Potatoes  .  . 

74.00 

26.00 

.80 

.42 

105 

Lobster  .  . 

76.62|23.38 

.81 

.42 

108 

Cabbage.. 

91.00 

9.00 

.93 

.48 

129 

Pigeon  .  .  . 

72.4027.60 

.78 

.41 

102 

Carrots.. 

83.  00117.  00 

.87- 

.45 

118 

Chicken.. 

73.7020.30 

.80 

.42 

105 

The  figures  in  the  last  co  umn,  showing  the  latent  heat  of  freezing,  have  been  obtained  by  multiplying 
the  latent  heat  of  freezing  water,  which  is  142  heat  un  ts,  by  the  per  cent,  of  water  contained  in  the  differen 
materials  considered,  for  as  the  solid  constituents  remain  in  their  original  condition   only  the  liquid  or  watery 
portion  of  these  materials  is  concerned  in  the  solidification  or  f  reezin|  of  them. 

THERMOMETER  SCALES. 


Cent. 

Reau. 

Fahr. 

Cent. 

Reau. 

Fahr. 

Cent- 

Reau. 

Fahr. 

-40 

—  &* 

—320 

—30.4 

—40.0 
-36  4 

Si 

22 

16.8 
17  6 

69.8 
71.6 

62 
63 

49.6 
50.4 

143  6 
143.4 

-36 

—  28  8 

—32  8 

23 

18.4 

73.4 

64 

51.2 

147.  2 

—34 

.—27.2 

-29.2 

24 

19.2 

73  *2 

65 

52.0 

149.0 

—3-2 

—25  0 

—  25  6 

25 

20.0 

77  0 

66 

52.8 

no.  8 

=8 

-24.0 
-22.4 

—  22.  0 

—  18.4 

26 
27 

20.8 
21.8 

73  8 
80.6 

67 

68 

53.6 
54.4 

152.6 
154.4 

—  2tt 

-20.8 

—14.8 

28 

22.4 

82.4 

69 

55.2 

156.2 

—24 
-22 
—20 

—  19.2 
—  17.6 
—  16.0 

—11.2 

—7.6 
—40 

29 

1? 

23.2 
24.0 

21.3 

84.2 
86.0 

87.8 

fj 

56.0 

56.8 
57.6 

158.0 

159.8 
161.6 

—18 

—14.4 

-0.4 

32 

25.6 

89.6 

73 

58.4 

163.4 

—10 

—  12.8 

+3.2 

33 

26.4 

91.4 

-74 

59  2 

165.2 

—  14 

—11.2 

6.S 

34 

27  2 

93.2 

75 

60.0          167.0 

I  -i 

—9.6 

10.4 

35 

2s!o 

95.0 

76 

60.8 

103.3 

—10    .    —8.0 

14  o 

30 

28.8 

96.8 

77 

61.6 

170.6 

-8         -6.4 

17.6 

37 

29.6 

93.6 

73 

62.4 

172.4 

-0 

—4.8 

21.2 

33 

30.4 

100.4 

79. 

63.2 

174.2 

—4 

—3.2 

24.8 

39 

31.2 

102.2 

80 

64.0 

176.0 

—2 

—1.6 

28.4 

40 

320 

104  o 

81 

64.8 

177.8 

—0 

0.0 

32  o 

41 

32.8 

105  8 

82 

65.6 

179.0 

+1 

+0.8 

33.8 

42 

33.  ti 

107.6 

83 

66.4 

131.4 

2 

1.6 

33.6 

43 

34.4 

109.4 

84 

67.2 

133/2 

3 

2.4 

37.4 

44 

35.2 

111.2 

85 

(53.0 

135.0 

4 

3.2 

39.2 

45 

36.0 

113.0 

8(3 

68.3 

186.3 

5 

4.0 

41.0 

46 

86.8 

114.8 

87 

69.6 

133.6 

6 

4.8 

42.8 

47 

37.6 

116.6 

83 

70.4 

190.4 

7 

5.6 

44.6 

48 

38.4 

113.4 

39 

71.3 

19i.2 

8 

6.4 

46.4 

49 

39.2 

120.2 

90 

72.0 

104.0 

.  9 

7.2 

48.2 

So 

40.0 

122.0 

91 

72.8     '     1J3.3 

10 

8.0 

50.0 

51 

40.8 

123.8 

92 

73.  G     !    197.6 

11 

8.8 

51.8 

52 

41.6 

125,6 

93 

74.4 

199.4 

12 

9.6 

53  6 

53 

42.4 

127.4 

94 

75.2 

201.2 

13 

10.4 

55.5 

54 

43.2 

129.2 

95 

76.0 

203.0 

14 

11.2 

57.2 

55 

44.0 

131.0 

96 

76.8 

•.'04.  3 

15 

12.0 

59.0 

56 

44.8 

132.8 

97 

77.6 

200  .  6 

16 

12.8 

60  8 

57 

45.6 

134.6 

98 

78.4 

203.4 

17 

13.6 

62.6 

5S 

46.4 

136.4 

99 

79.2 

210.2 

18 

14.4 

64.4 

59 

47.2 

133.2 

100 

8o.O 

2I2-.O 

19 

15.2 

66.2 

60 

48.0 

140.0 

2O 

16  o 

68.0 

61 

43.8 

141.8 

t. 

The  "Absolute  Zero"  of  temperature  denotes  that  condition  of  matter  at  which  heai 
ceases  to  exist.  At  this  point  a  body  would  be  wholly  deprived  of  heat  and  a  gas  would 
exert  no  pressure. 

The  Absolute  Zero  on  the  Fahrenheit  scale  is  about  461°  below  Zero. 
'•       "       Centigrade       "         "        274°      " 
Reamur  ••         "         219°      " 


Water 

Water  (H2O)  is  a  combination  of  one  atom  of  oxygen  and  two 
atoms  of  hydrogen. 

A  gallon  of  water  (U.  S.  standard)  weighs  8  1-3  Ibs.  and  con- 
tains 231  cu.  inches.  A  cu.  ft.  of  water  weighs  62.4  Ibs.  and  con- 
tains 1728  cubic  inches,  or  7.48  gallons. 

A  gallon  of  water  evaporated  at  atmospheric  pressure  will  pro- 
duce about  200  cu.  ft.  of  steam. 

A  gallon  of  water  evaporated  under  a  27-inch  vacuum  will  pro- 
duce about  2000  cu.  ft.  of  vapor. 

Water  containing  substances  in  solution  has  its  boiling  point 
raised. 

Pure  water  is  of  the  first  importance  in  an  ice  factory  both 
for  feeding  boilers  and  ice-making. 

Water  is  the  greatest  natural  solvent  known,  hence  is  rarely 
found  to  be  pure.  It  is  capable  of  absorbing  every  gas  and  vapor 
with  which  it  comes  in  contact. 

Solids  in  Water. 

Animal  life,  organic  matters,  such  as  sewage,  decayed  vegetable 
and  animal  matter,  poisonous  metals,  magnesia,  lime,  carbonates, 
sulphates,  alkalies,  earthy  salts,  chlorine  and  bromide  combina- 
tions, etc.,  are  found  in  quantity. 

Rules  for  Testing  Water. 

Water  turning  blue  litmus  paper  red  before  boiling,  which  after 
boiling  will  not  do  so ;  and  if  the  blue  color  can  be  restored  by 
warming,  then  it  is  varbonated  (containing  carbonic  acid). 

If  it  has  a  sickening  odor,  giving  a  black  precipitate  with  acetate 
of  lead,  it  is  sulphurous  (containing  sulphuretted  hydrogen). 

If  it  gives  a  blue  precipitate  with  yellow  or  red  prussiate  of 
potash  by  adding  a  few  drops  of  hydrochloric  acid,  it  is  chalybeate 
(carbonate  of  iron). 

If  it  restores  blue  color  to  litmus  paper  after  boiling,  it  i» 
alkaline. 

If  it  has  none  of  the  above  properties  in  a  marked  degree  and 
leaves  a  large  residue  after  boiling,  it  is  saline  water  (containing 
salts). 

Testing  by  Re-Agents. 

Water  is  not  pure  if  it  becomes  turbid  or  opaque  by  the  use  of 
the  following  agents  : 

Baryta  water  indicates  the  presence  of  carbonic  acid1. 

Chloride  of  barium  indicates  the  presence  of  sulphates. 

Nitrate  of  silver  indicates   the  presence  of  chlorides. 

Oxalate  of  ammonia  indicates  the  presence   of  lime  salts. 

Sulphide  of  hydrogen  slightly  acid  indicates  the  presence  of 
either  antimony,  arsenic,  tin,  copper,  gold,  platinum,  mercury,  sil- 
ver, lead,  bismuth  or  cadmium. 

Sulphide  of  ammonia,  alkaloid  by  ammonia,  indicates  the  pres- 
ence of  nickel,  cobalt,  manganese,  iron,  zinc,  alumina  or  chromium. 

Chloride  of  mercury  or  gold,  or  sulphate  of  zinc,  indicates  the 
presence  of  organic  matter. 

Water  may  be  found  which  will  pass  the  tests  above  described 
a^id  yet  be  unfit  for  use,  or,  as  it  is  commonly  called,  "not  potable." 
Distillation  is  the  only  method  to  produce  purity  in  water,  whereby 
all  deleterious  acids,  gases,  organic  and  mineral,  and  disease  germs 
can  be  eliminated1.  The  solid  and  organic  matter  held  in  suspense 
may  be  removed  by  filtration. 


AIR. 


Condensing  Water  for  Machinery. 

Water  for  use  in  the  ammonia  condensing  apparatus  is  preferred 
when  taken  from  springs  or  deep  wells,  for  the  reason  that  water 
from  below  the  surface  is  much  colder  than  surface  water,  hence 
much  less  is  required.  Water  from  considerable  depths  is  almost 
constant  in  temperature,  and  is  generally  from  50  to  56  degrees 
the  year  round,  while  water  from  rivers,  ponds  and  streams  ranges 
from  32  degrees  in  winter  to  95  degrees  in  midsummer.  The  colder 
the  water  used  in  the  condenser,  the  less  power  it  requires  to 
drive  the  machinery. 

For  refrigerating  machines  allow  about  1%  gallons  per  ton  refrig- 
erating capacity,  and  on  ice  plants  3  to  4  gallons  per  ton,  cUpend- 
«nt  upon  the  temperature. 


Air 

Air  is  a  mechanical  mixture  of  20.7  parts  oxygen  and  79.3  parts 
nitrogen  by  volume. 

The  weight  of  pure  air  at  32°  F.  and  atmospheric  pressure  Is 
0.081  Ibs.  per  cubic  foot.  Volume  of  1  Ib.  =  12,387  cu.  ft.  Air  ex- 
pands 1-491.2  of  its  volume  at  32°  F.  for  every  increase  of  1°  P. 

At  the  sea-level  its  pressure  is  14.7  Ibs.  per  sq.  inch.  At  one 
mile  above  12.02,  at  2  miles  9.8  Ibs.  Roughly,  the  pressure  de- 
creases 1/2  Ib.  for  every  1,000  feet. 

Moisture  in  Atmosphere. 

MOISTURE   CONTAINED   IN  ONE   CUB.    FT.   OF  SATURATED   AIR. 


Temp. 

4 

0 

5 
12 
14 
16 
18 
20 
22 
24 


Grains. 
0.5 
0.55 
0.73 
0.91 
1.05 
1.14 
1.23 
1.32 
1.41 
1.55 


Temp. 
26 
28 
30 
32 
34 
36 
38 
40 
42 
44 


Grains. 
1.69 
1.83 
1.97 
2.13 
2.32 
2.51 
2.7 
2.89 
3.08 
3.34 


Temp. 

46 

48 

50 

52 

62 

72 

82 

92 
102 
112 


Grains. 
3.6 
3.85 
4.12 
4.4 
6.17 
8.55 

11.67 

15.75 

21 

27.6 


REEXTIVE  HUMIDITY,  PER  CENT. 


Difference  between  the  Dry  and  Wet  Thermometers,  Deg.  F. 


vvta 

•&  G    • 
fr'Sg 

^  *"  Q 

a  ~ 

I 

2 

3 

• 

5 

6 

• 

6 

• 

,0 

11 

„ 

13 

14 

15 

16 

K 

18 

V. 

20 

21 

22 

23 

Q4 

20 

28 

Relative  Humidity,  Saturation  being  100.    (Barometer  =  30  ins.) 

32 
40 
50 
60 
70 
80 
00 
100 
110 
120 
140 

89 

92 
93 
94 

95 
90 
90 
JO 
97 
97 
97 

79 
88 

s, 

S9 
90 
91 
32 
93 
93 
94 
95 

39 

75 

SI! 

S3 
SO 
87 
S!) 
S9 
90 
91 
92 

59 
OS 
7-1 

7S 

81 

S3 
S5 
SO 
87 

ss 
89 

49 
(50 
(37 
73 
77 
79 
81 
S3 

SI 

sr, 
87 

39 
52 
61 

OS 
72 
75 

30 
45 

55 
63 

OS 

20 
37 
49 

58 
01 
f,s 

11 
29 

43 

53 
59 
61 

2 

3S 
48 
55 
61 

15 
3" 
43 

51 
57 
01 
65 
67 
09 
73 

27 

39 
4S 
54 

5S 

t;-2 
15 
67 
70 

0 
81 

34 

£ 

55 
59 

ii 

If, 

30 

•s 

:->2 
56 
BO 
62 

66 

11 
26 
36 
44 

-19 
54 
57 
50 
04 

21 

33 

r 
4< 

51 
55 
5S 
G2 

0 
17 
29 
38 
44 
49 
53 
-.:, 
10 

13 

25 
35 
41 
46 

-.0 

53 

58 

9 
22 
33 

39 
44 
48 
51 
5G 

5 

19 
29 
36 
41 
46 
49 
54 

1 
15 
26 

34 
i9 
44 
47 
53 

12 
23 

31 

37 
42 
45 
51 

9 
20 
29 
35 
40 
43 
49 

G 

18 
•JO 
33 
38 
41 
4', 

12 
22 

28 
3) 

44 

r- 

17 
24 
30 
34 
41 

so 
81 
83 

84 

78 
SO 

S2 

,  1 
73 

77 
79 

68 
70 

73 
74 

os 

70 
75 

EQUATION  OF  PIPES. 


The  relative  humidity  of  the  air  is  the  percentage  of  moisture 
contained  in  it  as  compared  with  the  amount  it  is  capable  of 
holding  at  the  same  temperature.  It  is  determined  by  the  use  of 
the  d'ry  and  wet  bulb  thermometer. 

Equation  of  Pipes. 

At  the  same  velocity  of  flow  the  volume  delivered  by  two  pipes 
of  different  sizes  is  proportional  to  the  squares  of  their  diameters  ; 
thus,  one  4-inch  pipe  will  deliver  the  same  volume  as  four  2-inch 
pipes. 

With  the  same  head,  however,  the  velocity  is  less  in  the  smaller 
pipe,  and  the  volume  delivered  varies  about  as  the  square  root  of 
the  fifth  power.  The  following  table  has  been  calculated  on  this 
basis.  Thus,  one  4-inch  pipe  is  equal  to  5.7  pipes  of  2-inch  diameter. 


c3  d 

1 

2 

3 

4 

5 

„ 

7 

;s 

9 

10 

12 

14 

16 

18 

20 

24 

2 

5.7 

1 

3 

15.6 

2.8 

1 

4 

32 

5.7 

2.1 

1 

5 

55.9 

9.9 

3.6 

1.7 

1 

6 

88.2 

15.6 

5  7 

2.8 

1.6 

1 

7 

130 

22.9 

'8.3 

4.1 

2.3 

1.5 

1 

8 

181 

32 

11.' 

5.7 

3.2 

2.1 

1.4 

1 

9 

243 

43. 

15.0 

7.6 

4.3 

2.8 

1.9 

1.8 

1 

10 

316 

55.9 

20.3 

9.9 

5.7 

3.6 

2.4 

1.7 

1.3 

1 

11 

401 

70.9 

25.7 

12,5 

7.2 

4.6 

3.1 

2.2 

1.7 

1.3 

12 

499 

88.2 

32 

15.6 

8.9 

5.7 

3.8 

2.8 

2.1 

1.6 

1 

13 

609- 

108 

39.1 

19 

10.9 

7."1 

4.7 

3.4 

2.5 

1.9 

1.2 

14 

733 

130 

47 

22.9 

13.  1 

8.3 

5.7 

4.1 

3.0 

2.3 

1.5 

15 

871 

154 

55.9 

•27.2 

15.6 

9.9 

6.7 

4.8 

3.6 

2  8 

1.7 

0 

16 

181 

65.7 

32 

18.3 

11.7 

r-  ( 

5.7 

4.2 

3.2 

!?.! 

'A 

17 

211 

76.4 

37.2 

•21  .3 

13.5 

9i2 

6.6 

4.9 

3.8 

2.4 

.6 

o 

18 

_•; 

243 

88.2 

43 

24.6 

15.6 

10  6 

7.0 

5.7 

4.3 

2.8 

.9 

\3 

1 

19 

278 

101 

49.1 

28.1 

17.8 

12.1 

8.7 

6.5 

5 

3.2 

2.1 

.5 

1.1 

20 

316 

115 

55.9 

32 

20.3 

13.8 

9.9 

7.4 

5.7 

3.6 

2.4 

.7 

1.3 

1 

22 

401 

146 

70.9 

40.6 

25.7 

17.5 

12.5 

9.3 

7.2 

4.6 

3.1 

2.2 

1.7 

1.3 

24 

499 

81 

88.2 

30.5 

32. 

21  -.8 

15.6 

11.6 

8.9 

5.7 

3.8 

2.8 

2.1 

1.6 

1 

26 

i. 

609 

221 

108 

61.7 

39.1 

26.6 

19. 

14.2 

10.9 

7.1 

4.7 

3.4 

2.5 

1.9 

1.2 

28 

733 

266 

130 

74.2 

47 

32 

22.917.1 

13.1 

8.3 

5.7 

4.1 

3 

2.3 

1.5 

30 
36 

871 

316 
499 

154 
243 

88.2 
130 

55.938 
88.260 

27.2 
43 

20.3 
32 

15.6 
24.6 

9.9 
15.6 

6.7 
10.6 

4.8 
7.6 

3.6 
5.7 

2.8 
4.3 

1.7 
2.8 

42 

.".  .j' 

733 

357 

205 

130  88.2 

63.2 

47 

36.2 

19 

15.6 

11.2 

8.3 

6.4 

4.1 

48 

•  /• 

499 

286 

181  123 

88.262.7 

50.5 

32 

21.8 

15.6 

11.6 

8.9 

5.7 

54 

CO 

'• 

£••: 

''*'• 

070 
871 

383 
499 

243  165 
316  1215 

118  88.267.8 
154  Jll5  188.2 

43 
55.9 

23.2 
38 

20.9 
27.2 

15.6 
20.3 

12   7.8 
15.6!  9.9 

Table  of  Standard   Steam,   Gas  or    Brine    Pipev 


twtdc 

iSSSTr 

Cireunifer- 

SR& 

Iol*m«l 

E»lenul 

P^°€f 

n& 

orrRSSi 

Con'CDK 
ntiftmf 

wag™ 

«r 

nBE* 

££, 

•Sr 

Incbel 

Inct'i 

C.SfcJoo, 

•HSSb- 

.5VSS 

p»t  Koo* 

w 

* 

.40 
.54 

1.272 
1.696 

44 
075 

.0572 
.1041 

.129 
.229 

2500. 
1385. 

24 
.42 

27 
18 

.0006 
.0028 

.005 
021 

./ 

.67 

2.121 

.657 

.1916 

.358 

751.5 

.56 

18 

.0057 

.047 

C 

.84 

2.652 

55 

.3048 

.554 

472.4 

.84 

14 

.0102 

.085^ 

^ 

1.05 

3.299 

.637 

.533 

.866 

270. 

1.12 

14 

0230 

.190 

. 

1.31 

4.134- 

.903 

.862 

357 

166.9 

1.67      ' 

UK 

.0408 

'  .349 

i  if 

1.66 

5.215 

.301 

1.496 

184 

96.25 

2.25 

.0638 

.527  i 

IK 

i.O 

•5.969 

.01 

2.038 

835 

70.65 

2.69 

HH 

.0918 

.760 

3 

2.3t 

f.481 

.611 

3.355 

430 

42.9 

3.66 

l  X 

.1632 

1.356 

2.87 

9032 

.328 

783 

491 

30.11 

5.77 

.2550 

2.116 

. 

3.5 

.10.996 

.091 

388 

621 

1    49 

754 

.3673 

3.049 

3tf 

12.566 

.955 

887 

1    566 

1    66 

905 

.4998 

4.155 

* 

4.5 

14.137  . 

.849 

1    73 

1    904 

1    31 

1072 

.6528 

5.405 

..* 

5. 

1S.7CS 

.765 

1    96 

19.635 

03 

12.34 

.8263 

6.851 

5 

5.56 

17  475 

.69 

1    99 

24.299 

20 

14.56 

020 

8.500 

0 

6.63 

20.813 

.577 

28.889 

34.471 

.98 

18.76 

.489 

12.312 

762 

23954 

.505 

38.737 

45.663 

72 

23.41 

999 

16.662 

• 

8.62 

27096 

.444 

50.039 

58.426 

88 

28.34 

.611 

21  750 

9, 

968 

30433 

.394 

63.633 

73.715 

26 

34.67 

.300 

27500 

10 

ia?5 

13.772 

355 

.78.838 

90.762 

.80 

40.64 

.081 

34.000 

Refrigerating   Media 


The   efficiency  of  a  gas  depends  on  three  properties: 

First,  a  low  boiling  point,  upon  which  depends  the  degree  of 
cold  that  can  be  produced. 

Second,  a  high  latent  heat  of  evaporation,  upon  which  depends 
the  total  number  of  heat  units,  which  will  be  abstracted  by  the 
evaporation  of  a  given  weight  of  the  medium. 

The  following  diagrams  are  reproduced  from  N.   Selfe. 


TEMPERATURE        AT      BOIUNC         POINTS 


Third,  a  low  specific  heat,  upon  which  depends  the  amount  of 
refrigeration  produced  which  can  be  actually  utilized. 

Ammonia. 

Ammonia,  H8N,  is  composed  of  one  part  of  nitrogen  and  three 
parts  hydrogen.  It  can  be  obtained  from  the  air,  from  sal-ammo- 
niac, nitrogenous  constituents  of  plants  and  animals  by  process  of 
distillation — as  a  matter  of  fact,  there  are  very  few  substances  free 
from  it.  At  the  present  day  almost  all  the  sal-ammoniac  and 
ammonia  liquors  are  prepared  from  ammoniacal  liquid,  a  by-product 
obtained  in  the  manufacture  of  coal  gas. 

Pure  ammonia  liquid  is  colorless,  having  a  peculiar  alkaline 
odor  and  caustic  taste.  It  turns  red  litmus  paper  blue. 

Its  boiling  point  depends  on  its  purity,  and  is  about  28  6-10 
degrees  below  zero  at  atmospheric  pressure. 

Compared  with  water,  its  weight  or  specific  gravity  at  32  dtegreei 
F.  is  about  5-8  of  water,  or  0.6364. 

One  cubic  foot  of  liquid  ammonia,  weighing  39.73  pounds,  one 
gallon  weighs  §  and  3-10  pounds,  one  pound  of  the  liquid  at  32°,  will 
occupy  21.017  cubic  feet  of  space  when  evaporated  at  atmospheric 
pressure. 

Its  latent  heat  of  evaporation  is  not  far  from  560  thermal  units 
at  32  degrees,  at  which  temperature  one  pound  of  liquid,  evap- 
orated under  a  pressure  of  fifteen  pounds  per  square  Inch,  will 
occupy  twenty-one  cubic  feet. 


8  AMMONIA. 

Ammonia  liquid  should  be  pure.  Its  purity  may  be  tested  by 
the  following  simple  methods  recommended  by  the  Frick  Co.  and 
other  build'ers  : 

Testing   for   Water  "by  Evaporation. 

Screw  into  the  ammonia  flask  a  piece  of  bent  one-quarter  inch 
pipe,  which  will  allow  a  small  bottle  to  be  placed  so  as  to  receive 
the  discharge  from  it.  Fill  the  bottle  about  one-third 


.zo 


2 

uj-o 


LATENT    HEAT  or  VAPORIZATION 

=    Per  Pound  of  Medium  — 

—  IN   BRITISH    THERMAL    UNITS  

With    pKiVicifrAl    Media.    Used    m   Qefvige*dT\r\q    Machines 


full,  and  throw  sample  out  in  order  to  purge  valve,  pipe 
and  bottle.  Quickly  wipe  off  the  moisture  which  has  accumulated 
on  the  pipe,  replace  the  bottle  and  open  valve  gently,  filling  the 
bottle  about  half  full.  This  last  operation  should  not  occupy  more 
than  one  minute.  Remove  the  bottle  at  once  and  insert  in  its  neck 
a  stopper  with  a  vent  hole  for  the  escape  of  the  gas.  Procure  a 
piece  of  solid  iron  that  should  weigh  not  less  than  8  or  10  pounds, 
pour  a  little  water  on  this  and  place  the  bottle  on  the  wet  place. 
The  ammonia  will  at  once  begin  to  boil,  and  in  warm  weather  will- 
ammonia  will  at  once  begin  to  boil,  and  in  warm  weather  will 
soon  evaporate.  If  it  shows  any  residluum,  pour  it  out  gently, 
counting  the  drops  carefully.  Eighteen  drops  are  about  equal  to 
one  cubic  centimeter,  and  if  the  sample  taken  amounted  to  100 
cubic  centimeters,  you  can  readily  approximate  the  percentage  of 
the  liquid  remaining. 

Test  for  Inflammable  Oases. 

Take  a  pail  of  water,  submerge  the  bent  end  of  quarter-Inch 
pipe  therein,  open  the  valve  on  flask  slightly,  and  allow  a  small 
quantity  of  gas  to  flow  into  the  water.  If  inflammable  gases  ar* 


AMMONIA.  9 

present,  they  will  rise  in  bubbles  to  the  surface  of  the  water,  and 
may  be  proved  by  igniting  the  bubbles  by  means  of  a  lighted 
cand'le  or  match.  As  water  has  a  strong  affinity  for  ammonia,  it 
will  be  readily  absorbed,  while  air  or  other  gases  will  show  only 
in  the  form  of  bubbles. 

Test  for  Specific  Gravity. 

The  specific  gravities  of  liquid  ammonia  by  Beaume  scale  are 
given  in  table  below  ;  by  drawing  off  some  of  the  liquid  in  a  tall 
test  tube,  the  Beaume  Hydrometer  (light)  may  be  inserted  and  the 
specific  gravity  read  upon,  the  scale.  If  water  is  present,  the 
liquid  will  show  a  density  proportionate  to  the  percentage  of  the 
water  present. 

Specific  gravity  of  pure  anhydrous  ammonia  is  .623. 

Test  for  Boiling  Point. 

By  inserting  a  special  low  temperature  standardized  chemical 
thermometer  into  liquid  drawn  into  the  8-oz.  test  jar,  readings 
can  be  obtained  through  the  side  of  the  jar  without  removing  the 
instrument.  Hold  the  thermometer  in  such  position  that  only  the 
bulb  is  immersed.  This  test  will  give  you  the  boiling  point  of 
ammonia  at  atmospheric  pressure,  and_Jt  is  well  to  know  that  the 
state  of  the  barometer  affects  the  temperature  of  the  boiling  point. 
With  the  barometer  at  29.92  inches,  the  boiling  point  is  nearly 
28  6-10  degrees  below  zero.  If  the  ammonia  is  impure,  the  boiling 
point  is  raised  in  proportion. 

To  Test  Brine  or  Water  for  Ammonia. 

"Nessler's  Reagent"  is  used  extensively.  It  is  prepared  as  fol- 
lows :  Dissolve  17  grams  of  mercuric  chloride  in  cubic  centimeters 
of  distilled  water;  disserve  35  grams  of  potassium  iodide  in  100 
cubic  centimeters  of  water ;  stir  the  latter  solution  into  the  first 
until  a  red  precipitate  is  thrown  down.  Then  dissolve  120  grams 
of  potassium  hydrate-  in  200  cubic  centimeters  of  water  and  allow 
the  solution  to  cool,  then  add  to  the  other  solution,  and  add 
sufficient  water  to  make  one  litre.  Then  add  mercuric  chloride 
solution  until  a  precipitate  forms.  Let  this  settle  and  decant  off 
a  clear  solution. 

Keep  the  solution,  in  glass  stoppered  blue  bottles.  A  few  drops 
of  this  solution  added  to  a  sample  of  brine  or  water  will  cause  the 
brine  or  water  to  turn  yellow  if  a  small  percentage  of  ammonia 
is  present  and  turn  to  a  full  brown  if  the  percentage  of  ammonia 
is  large. 

Impurities   Test. 

When  testing  ammonia  for  impurities,  it  is  diluted!  with  twice 
its  volume  of  distilled  water.  It  is  then  made  acid  with  hydro- 
chloric acid.  Then  to  detect  the  presence  of  sulphates,  add  a 
solution  of  chloride  of  barium.  If  sulphates  are  present,  a  white 
precipitate  will  be  formed.  To  detect  the  presence  of  chlorides 
the  solution  of  ammonia  and  water  is  acidulated  with  nitric  acid 
instead  of  hydrochloric,  and  the  white  precipitate  is  formed  by 
the  addition  of  a  nitrate  of  silver  solution.  But  if,  in  this  case, 
red  appears,  there  is  evidence  of  organic  matter. 

Aqua  Ammonia. 

16°  aqua  ammonia,  often  called"  by  druggists  F.F.F.,  containing  a 
little  more  than  10  per  cent  of  pure  anhydrous  ammonia,  18* 
aqua  ammonia  (F.F.F.F.)  containing  nearly  14  per  cent  of  anhy- 
drous ammonia.  26°  aqua  ammonia  ("stronger  aqua  ammonia") 
containing  29%  per  cent  of  pure  anhydrous  ammonia.  This  is 
generally  used  in  absorption  plants  for  the  start. 


10  AMMONIA. 

PROPERTIES  OF   SATURATED  AMMONIA. 


1 

p 

isU 

W 

ill 

b 
I 

i 

Absolute  Temp. 
Degrees  P. 

,atent  Heal  of 
Evaporation  in 
Thermal  Units. 

-1 

"o 

0  0 

III 

'5>'J' 

fy 

o£.s 

«!! 

|u> 

4£ 

qJ 

PI 

l-Su 

|1 

y 

in 

—4.01 
—2.39 
—0.57 
+1.47 
3.75 

1069 
12.31 
14.13 
16.17 
1845 

—40 
—35 
—30 
—25 
—20 

420.CG 
425.CG 
430.06 
435.  GO 
440.  GG 

57967 
576.68 
573.  G9 
570.08 
567.67 

24.38 
21  32 
1869 
16.44 
14.51 

04iO 
.0469 
.0535 
.0008 
.0690 

.0234 
.0230 
0237 
0238 
02-10 

42  589 
42337 
42.123 
41  858 
41.615 

C29 
0.10 
12.22 
15.C7 
1946 

20.99 
?380 
'2692 
3037 
3416 

IX 

—10 
—5 
0 

±s 

445:66 

450.  GC 
45566 
46066 
4G5G6 

504.64 
561.61 
558.56 
555  50 
552.43 

12.83 
11.38 
10.12 
9.03 

8.07 

.0779 
.0878 
.0988 
.1107 
.1240 

.0241 
.0243 
.0244 
.0240 
0247 

41.374 
41  135 

40  900 
40  650 
40  404 

23  G4 
28.24 
8325 
38.73 
4472 

38.34 
42  94 
47  95 
53.43 
59.42 

10 
15 

20 
25 
30 

470.  GG 
475.GG 
480.66 
485  C6 
490  66 

54935 
540.26 
543.15 
540.03 
536.91 

723 
6.49 
584 
5.27 
4  76 

.1383 
.1541 
.1711 

.1897 
.2099 

.0249 
.0250 
.0252 
.0253 
.0255 

40  100 
39.020 
39G32 
39  432 
39.200  , 

51.22 
58.29 
65.96 
7426 
83.22 

6592 
7299 

8066 
88.96 
97.92 

35 
40 
45 
50 
55 

495  GG 
500.66 
505  C6 
510.  GO 
515.66 

•533.78 
530.63 
527  47 
524.30 
521.12 

431 
3.91 
3.56 
3  24 
2.9G 

.2318 
2554 
.2809 
.3084 
.3380 

.0250 
.0258 
.0200 
.02C1 
.0263 

38  940 
38684 
3B4G1 
38  226 
37  994 

92.89 
103.33 
11449 
126.52 
139.40 

107.59 
118.03 
129.19 
141.22 
154.10 

60 
65 
70 
75 
80 

520.66 
525.66 
530.66 
535.66 
540.  GG 

51793 
514.73 
511.52 
508.29 
505.05 

2.70 
248 
2  27 
209 
1  92 

.3097 
.4039 
4401 
4791 
.5205 

.0265 
.0266 
.0268 
.0270 
.0272 

37  736 
37481 
37  t:iO 
36  993 
56  751 

153.18 
167.92 
183.65 
200.42 
•218.28 

167.88 
182.62 
198.35 
215.12 
232.98 

85 
90 
95 
100 
105 

545.G6 
55066 
555.06 
500.66 
5G5.GG 

501  81 

498.55 
495.29 
49201 
488.72 

1  77 
1  64 
1  51 
1  39 
1.289 

504  9 
.6120 
.6622 
7153 

7757 

.0273 
.027o 
0277 
0279 
.0281 

36  509 
3G.2o8 
36  O2.'f 
35  778 

23727 

258  7 

251.97 
272  14 

110 
115 

570.  CG 
575  GG 

485.42 
48°  41 

1.203 
1  121 

.8312 
891° 

.0283 
0285 

275.79 
SOI  .46 
825.72 

293.49 
31616 
340  42 

120 
125 
130 

580.  CG 
585  06 
590.06 

478.79 
475.45 
472.11 

1.041 
.9G99 
.9051 

.9608 
0310 
1048 

.0287 
0289 
0291 

350.46 
37752 
405  19 
435.5 
46684 
49970 
53434 

365.16 
392.22 
420.49 
450.20 
481.54 
514.50 
54904 

135 
140 
M5 
150 
155 
160 
165 

59566 
600.66 
605.  GG 
610  66 
615  GG 
62066 
625.  GG 

46875 
465.39 
462.01 
45862 
45522 
451  81 
448.39 

.8457 
.7910 
.7408 
.6946 
.6511 
.6128 
.5705. 

.1824 
2G42 
'3497 
4  390 
5358 
0318 
7344 

.0-^93 
.0295 
0297 
.0299 
0302 
0304 
.0306 



STRENGTH   OP  AMMONIA   LIQUOR. 


H 

o 

vi) 

d 

<j   • 

MJ 

ES 

BO 

E° 

BO 

^  o|> 

d,S 

|& 

§fe 

*o  o  ^ 

c^- 

«^ 

?  u 

03  <U 

*!* 

Wfc 

ttd 

0      P 

«| 

d 

Mfc 

<D.2i 

?l 

«I 

.0. 

1.000 

10 

0 

20 

0.925 

21.7 

11.2 

1 

0.993 

11 

1 

22 

0.919 

22.8 

12.3 

2 

0.986 

12 

2 

24 

0.913 

23.9 

13.2 

4 

0.979 

13 

3 

26 

0.907 

24.8 

14.3 

6 

0.972 

14 

4 

28 

0.902 

25.7 

15.2 

8 

0.966 

15 

5 

30 

0.897 

26.6 

16.2 

10 

0.960 

16 

6 

32 

0.892 

27.5 

17.3 

12 

0.953 

17.1 

T 

34 

0.888 

28.4 

18.2 

14 

0.945 

18.3 

8.2 

36 

0.884 

29.3 

19.1 

16 

0.938 

19.5 

9.2 

38 

0.880 

30.2 

20.0 

18 

0.931 

•20.7 

10.3 

CARBONIC  ACID.  n 

Carbonic  Acid. 

Carbonic  anhydride,  or  carbonic  acid  as  it  is  usually  called1,  has 
the  chemical  designation  Carbon  Dioxide,  CO2,  and  consists  of  two 
atoms  of  oxygen  and  one  atom  of  carbon. 

The  chief  characteristics  of  the  gas  are  absence  of  odor,  neutral- 
ity towards  materials  and  food  products,  the  fact  that  it  cannot 
be  decomposed  under  pressure  and  its  cheapness.  It  has  a  specific 
gravity  of  1.529  (air  is  1)  at  atmospheric  pressure  and  becomes  a 
liquid  at  124  degrees  below  zero,  Fahr.,  or  156  degrees  below  the 
freezing  point  at  that  pressure. 

Atmosphere  containing  8  per  cent  of  carbonic  anhydride  can  be 
inhaled  without  causing  inconvenience  or  leaving  any  deleterious 
effects  upon  the  human  system.  Carbonic  anhydride  will  fall  to 
the  floor  by  reason  of  its  greater  specific  weight,  and  even  in  the 
event  of  a  serious  leak  occurring,  the  air  will  not  become  suffi- 
ciently saturated  to  cause  any  harm. 

Fifteen  per  cent  (15%)  of  carbonic  anhydride  in  the  atmosphere 
will  extinguish  fire. 

Carbonic  anhydride  is  artificially  produced  in  pure  form  by 
means  of  combustion  of  chalks  and  magnesite,  or  by  means  of  the 
decomposition  of  marble  with  sulphuric  or  nitric  'acid. 

The  so-called  Pistet  fluid  is  a  mixture  of  carbonic  acid  and  sul- 
phur dioxide,  which  according  to  Pictet  is  expressed  by  the  chem- 
ical symbol  CO^S.  The  pressure  of  this  mixture  at  higher  tem- 
perature is  said  to  be  less  than  the  law  of  corresponding  pressures 
and  temperatures  would  indicate.  According  to  this  there  would  be 
less  work  required  of  the  compressor. 

Ethyl  chloride  (C2H5C1)  has  been  used  during  the  last  few  years 
as  a  refrigerating  medium,  although  to  very  little  extent.  Its 
boiling  point  at  atmospheric  pressure  is  about  54°  F.  In  order, 
therefore,  to  produce  cold,  the  machine  has  to  work  under  vacuum, 
while  the  condenser  pressure  hardly  ever  exceeds  15  Ibs.  The  gas 
is  neutral  towards  metals,  its  critical  temperature  is  at  365°  F. 
It  is  more  expensive  than  any  of  the  other  media,  but  it  is  claimed, 
that  on  account  of  the  low  pressure  there  will  hardly  be  any  loss 
of  gas. 

Methyl  chloride  machines  are  comparatively  new  and  not  In 
practical  use  to  any  extent  so  far. 

Certain  hydrocarbons,  naphtha,  gasoline,,  etc.,  have  also  been 
experimented  with  as  refrigerating  media.  All  these  liquids  possess 
the  same  great  inflammability  as  ether,  but  they  are  cheaper. 

Acetylene  (C2H2),  the  once  heralded  illuminating  agent  of  the 
future,  has  also  been  mentioned  as  a  possible  medium.  It  is 
highly  inflammable.  It  liquifies  at  32°  F.  under  a  pressure  of 
48  atmospheres. 

Liquid  air  has  also  been  prominently  spoken  of  as  a  refrigerat- 
ing medium.  But  under  present  conditions  its  production  is  too 
expensive  to  render  it  available  for  ordinary  refrigeration.  Its 
usefulness  is  limited  to  produce  extremely  low  temperatures,  which 
may  be  required  for  special  purposes  in  the  laboratory. 


Brine 

Until  recent  years  brine  was  made  by  dissolving  common  salt, 
NaCl  (chloride  of  sodium)  in  water.  Later  chloride  of  magne- 
sium was  used  instead.  The  latter  was  neutral  to  iron  and  did"  not 
freeze  at  extremely  low  temperatures.  Later  still,  because  of  the 
high  cost  of  chloride  of  magnesium,  chloride  of  calcium,  Cads, 
having  nearly  the  same  properties  as  choloride  of  magnesium,  was 
used  either  direct  or  in  combination  with  chloride  of  magnesium. 

Chloride  of  Sodium. 

When  using  common  salt,  buy  in  bags,  containing  medium  ground 
pure  salt.  Allow  about  three  Ibs.  per  gallon  of  water.  Continue  to 
dissolve  the  salt  in  the  brine  tank  until  it  reaches  a  density  of  85 
to  90  degrees  by  salt  gauge.  The  stronger  the  brine  the  lower 
temperatures  can  be  obtained  without  freezing. 

In  making  the  brine  it  is  well  to  use  a  water-tight  box,  say  4ft. 
wide,  8  ft.  long,  and  2  ft.  high,  with  a  perforated  false  bottom  and 
compartment  at  end. 

Locate  the  brine  maker  at  a  point  above  the  brine  tank.     Con- 


Salt  Gauge 


Salt 


FIG.   1— METHOD  OF  MAKING  BRINE. 


nect  the  space  under  the  false  bottom  with  your  water  supply, 
extending  the  pipe  lengthways  of  the  box  and  perforated  at  each 
side  to  insure  an  equal  distribution  of  water  over  the  entire  bot- 
tom surface,  use  a  valve  in  water  supply  pipe.  Near  the  top  of 
the  brine  maker  at  end  compartment,  put  in  an  overflow-  with 
large  strainer  to  keep  back  the  dirt  and  salt,  and  connect  with 
this  a  pipe,  say  3  ins.  diameter,  with  salt  catcher  at  bottom  leading 
into  the  brine  tank.  Use  a  hoe  or  shovel  to  stir  the  contents. 
When  all  is  ready  partly  fill  the  box  with  water,  dump  the  salt  from 
the  bags  on  the  floor  alongside  and  shovel  into  brine  maker,  or 
dump  direct  from  the  bags  into  brine  maker  as  fast  as  it  will  dis- 
solve ;  regulate  the  water  supply  to  always  insure  the  brine  being 
of  the  right  strength  as  it  runs  into  the  brine  tank  :  this  point  must 
be  carefully  noticed. 

Filling  the  brine  tank  with  water  and  attempting  to  dissolve  the 
salt  directly  therein  is  not  satisfactory,  as  quantities  of  salt  settle 
on  the  tank  bottom  coils,  forming  a  hard  cake. 

When  desired  to  strengthen  the  brine,  suspend  bags  of  salt  in 
the  tank,  the  salt  dissolving  from  the  bags  as  fast  as  required, 
or  the  return  brine  from  the  pumps  may  be  allowed  to  circulate 
through  the  brine  maker,  keeping  same  supplied  with  salt. 


BRINE.  13 

Chloride  of  Calcium. 

Fused  Calcium.  Commercial  calcium  is  made  by  melting  the 
crystals  at  400°  F.,  thus  driving  off  the  water  of  crystallization, 
leaving  the  remainder  75  per  cent  calcium  and  25  per  cent  water. 
This  solution,  while  hot,  is  poured  into  iron  drums  and  sealed  up 
air  tight.  This  calcium  comes  in  600  to  700  pound  iron  drums, 
which  should  be  painted  with  asphalt  varnish,  so  that  they  can  be 
stored  away  in  damp  and  cold  rooms  without  danger  of  rusting. 

When  making  brine,  the  calcium  should  be  broken  up  into  pieces 
and  placed  in  a  barrel  or  tank  with  perforated  bottom.  Then  the 
water  or  brine  should  be  pumped  over  it  until  the  brine  is  of  the 
required  strength.  To  break  up  the  calcium,  hit  the  drums  a  num- 
ber of  heavy  blows  with  a  sledge  hammer,  the  iron  cover  can  then 
be  removed  with  a  cold  chisel  and  the  calcium  will  be  found  to 
be  broken  up  as  desired. 

Heat  is  generated  as  the  calcium  dissolves  and,  if  possible  to  do 
so,  it  will  be  found  more  convenient  to  dissolve  the  calcium  when 
the  brine  is  not  being  refrigerated.  It  dissolves  more  rapidly  in 
warm  or  hot  than  in  cold  brine.  Steam  can  be  used  to  advantage 
for  the  rapid  dissolving  of  large  quantities  of  chloride  of  calcium. 

Fluid  Calcium  :  This  is  of  1400  specific  gravity  (weighing  11.66 
pounds  per  gallon),  and  contains  about  40  per  cent  of  anhydrous 
chloride  of  calcium  in  solution  ;  it  is  water  white  and  clear.  It  is 
shipped  in  tank  cars  of  4,500  gallons.  When  diluted  with  an 
equal  volume  of  water,  it  gives  a  solution  of  1,200  specific  gravity, 
which  is  strong  enough  for  most  purposes..  Calcium  fluid  of  spe- 
cific gravity  of  1600  (weighing  13.32  pounds  per  gallon),  contain- 
ing up  to  60  per  cent  of  anhydrous  chloride  of  calcium  in  solution 
crystallizes  into  a  semi-solid  mass  in  cool  weather,  and  it  is  neces- 
sary to  warm  it  up  to  60°  Fahr.,  which  makes  it  rather  difficult 
to  handle  during  cool  weather,  unless  steam  is  conveniently  at 
hand.  The  1,600  specific  gravity,  or  60  per  cent  solution,  when 
diluted  with  two  parts  of  water,  gives  a  brine  of  1,200  specific 
gravity. 

A  solution  of  chloride  of  sodium  brine,  twenty-five  per  cent  by 
weight,  is  saturated  and  will  freeze  at  0°  F.,  but  will  tend  to 
separate  the  salt  and  begin  to  freeze  at  5°  F.  A  solution  of 
chloride  of  calcium,  twenty-five  per  cent  by  weight,  freezes  at 
— 22°  F.  In  can  ice  making  the  brine  is  usually  carried  at  10°  to 
16°  F.,  which  requires  ammonia  at  from — 5°  F.  to  5°  F.  At  these 
temperatures  salt  will  separate  out  and!  ice  will  form  on  the  ex- 
pansion coils,  thereby  insulating  them  and  requiring  a  lower  back 
pressure. 

Chloride  of  calcium  brine  of  1.22  specific  gravity  has  twenty- 
four  per  cent  of  calcium  chloride  by  weight,  or  four  pounds  to  the 
gallon.  This  brine  freezes  at— 17°  F.,  and  in  can  ice  making  can 
be  diluted  with  thirty  per  cent  of  water  before  it  will  freeze,  as 
will  a  saturated  salt  brine  solution.  Chloride  of  calcium  brine  hav- 
ing two  and  one-half  to  three  pounds  to  the  gallon  is  all  right  for 
ice  making.  In  brine  tanks  the  salt  brine  freezes  on  the  coils  and 
insulates  them,  or  in  brine  coolers  freezes  in  the  coils  and  breaks 
them.  Salt  brine  loses  in  evaporation,  some  of  the  salt  being  car- 
ried away,  while  calcium  brine  does  not. 

Aside  from  its  stability  to  stand  lower  temperatures,  calcium 
chloride  has  the  advantage  over  sodium  chlorid'e  or  salt  brine  of 
having '  absolutely  no  action  upon  iron,  thus  materially  increasing 
the  life  of  brine  tanks  and  brine  coils.  While  the  cost  of  calcium 
chloride  is  somewhat  greater  than  salt,  this  is  offset  to  some  extent 
by  the  fact  that  25  per  cent  less  calcium  than  salt  is  required. 


BRINE. 


TABLE  OF  CALCIUM  BRINK  SOLUTION. 


Deg. 

Baumg 
00°  F. 

Deg. 
Salom- 
eter. 
60°  F. 

Per  Cent 
Calcium 
by  Weight 

Lbs.  per 
Cu.  Ft. 
Sol. 

Lbs. 
per 
Gallon 

Specific 
.  Gravity 

Specific 
Heat 

.Point  F. 

Amm. 
Gauge 
Pressure 

0 

0 

0 

0       . 

0 

'    1 

1 

82 

47.31 

1 

4 

.943 

1.25 

J 

1.007 

.996 

31.1 

46.14 

2 

8 

1.886 

2.5 

| 

.014 

.988 

3033 

45-14 

3 

12 

2.829 

375 

1 

.021 

.98 

29.48 

44.06 

4 

16 

3.772 

5 

I 

.028 

.972 

28.58 

43 

5 

20 

4.715 

6.25 

1 

.036 

.964 

27.82 

42.08 

6 

24 

5.658 

7.5 

1 

1.043 

.955 

27.05 

41.17. 

7 

28 

6.601 

8.75 

JJ 

1.051 

.946 

26.28 

4025 

8 

82 

7.544 

10 

u 

1.058 

.936 

25.52 

39.35. 

9 

36 

8.487 

11  25 

1* 

.066 

.925 

24.26 

37.9 

10 

40 

9.43 

12.5 

.074 

.911 

22.8 

36.3 

11 

44 

10.373   ' 

13.75 

11 

1.082 

.896 

21.3 

34.67 

12 

48 

11  316 

15 

2 

1.09 

.89 

19.7 

32.93 

13 

52 

12.259 

16.25 

2| 

1.098 

.884 

18.1 

31.33 

14 

56 

1320? 

17.5 

2* 

1.107 

.878 

16.61 

29.63 

15 

60 

14.145 

18.75 

1.115 

.872 

.15.14 

28.35 

16 

64 

15.088 

20 

2|  § 

1.124 

.866 

13:67 

27.04 

17 

68 

16031 

21.25 

1.133 

.86 

12.2 

25.78 

18 

72 

16974 

22.5 

3 

1.142 

.854 

10 

2385 

19 

76 

17917 

23.75 

3} 

1.151 

.849 

7.5 

21.8 

20 

80 

18.86 

25 

8* 

1.16 

.844 

4.6 

19.43 

21 

84 

19803 

26.25 

3J 

1.169 

.839 

1.7 

17.  0« 

22 

88 

20.746 

27.5 

31 

1.179 

.834 

—  1.4 

14.7 

23 

92 

21.689 

28.75 

8f 

1.188 

.825 

—  4.9 

12.2 

24 

96 

22.632 

30 

4 

1.198 

.817 

—  8.6 

9.96 

25 

100 

23.575 

31.25 

4i 

1.208 

.808 

—11.6 

8.19 

26 

24.518 

32.5 

4j 

1.218 

.799 

^17.1 

5.22 

27 

25.461 

33.75 

4i 

1.229 

.79 

—21.8 

2.94 

28 

26.404 

35 

41 

1.239 

.778 

—  27. 

.65 

29 

27347 

36.25 

1.25 

.769 

—32.6 

T'Vac. 

30 

28.29 

37.5 

5 

1.261 

.757 

-39.2 

8.5"" 

TABLE  QF  CHLORIDE  OF  SODIUM  (SALT)  BRINE. 


Degrees 
on 
Salom. 

Percent- 
age Salt 
by  Weight 

Pounds 
Saltper 
Cu.  Ft. 

Poun3s 
Saltper 
Gallon 

'  Specific 
Gravity 

Specific 
Heat 

Freezing 
Point  F. 

Ammonia 
Gauge 
Pressure 

P 

0 

0 

0 

1 

1 

32 

47.83 

5 

1.25 

.785 

.105 

1.009 

.99 

303 

45.1 

10 

2.5 

1.586 

.212 

1.0181 

.98 

286 

43.03 

15 

3.75 

2.401 

.321 

1.0271 

.97 

26.9 

41 

20 

5 

3.239, 

.433 

1.0362 

.96 

25.2 

88.96 

25 

6.25 

4.099 

.548 

.0455 

.943 

23.6 

87.19 

80 

7.5 

4.967 

.664 

10547 

.926 

22 

8544 

85 

875 

5.834 

.78 

.064 

.909 

204 

83.69 

40 

10 

6709 

.897 

.0733 

.892 

18.7 

81  98 

45 

11.25 

7.622 

1.019 

.0828 

.883 

17.1 

80.33 

50 

125 

8.542 

1.142 

0923 

.874 

15.5 

•28.73 

65 

13.75 

9.462 

.265 

1018 

.864 

13.9 

27.24 

60 

15 

10.389 

.889 

.1114 

.855 

122 

2576 

65 

16.25 

11.384 

.522 

..1213 

.848 

10.7 

24.46 

70 

175 

12  §87 

.656 

.1312 

.842 

9.2 

23.16 

75 

18.75 

13396 

791 

.1411 

.835 

7.7 

21  82 

80 

20 

14421 

928 

.1511 

.829 

61 

2043 

85 

21  25 

15.461 

2.067 

1614 

.818 

4.6 

1916 

90 

22.5 

16508 

2.207 

1717 

.806 

3.1 

182 

95 

23.75 

17555 

2.347 

.182 

795 

1.6 

16.88 

100 

25 

18.61 

2.488 

1923 

.783 

0 

1567 

PART   II— REFRIGERATING    MACHINERY 


Looking  back  in  history  we  read  in  the  Songs  of  Solomon  that 
in  ancient  times  snow  was  used  for  the  cooling  of  food  and  drink. 
The  Kalif  Mahdi  (775)  is  said  to  have  received  shipments  of  snow 
by  camels  at  Mecca,  also  the  Sultan  in  the  year  10UO  had  ice 
shipped  continuously  from  Syria  for  his  kitchen. 

The  cooling  of  water  by  means  of  mixtures  of  snow  and  salpeter 
was  known  to  the  Chinese  already  in  the  twelfth  century. 

Freezing  mixtures  of  different  salts  with  ice  or  snow  appeared 
in  Europe  in  the  year  1550  in  various  compositions.  This  method! 
of  producing  cold,  however  old,  is  still  in  every  day  use  for  such 
purposes  as  freezing  ice  cream. 

FREEZING    MIXTURES. 


Ammonium    nitrate.  .  . 
Water    
Ammonium    chloride.  . 
Potassium    nitrate.  .  .  . 
Water    
Ammonium    chloride..! 
Potassium    nitrate.... 
Sodium    sulphate  

1 

[  From-|-400  to  +  4° 
j-  From+50°  to  +  10° 

L  From  +  50°  to  +  4° 

Snow  or  pounded  Ice  .  . 
Sodium   chloride  .' 
Snow  or  pounded  Ice.  . 
Sodium   chloride  
Ammonium    chloride.. 
Snow  or  pounded  Ice.  . 
Sodium   chloride  
Ammonium    chloride.  . 

4 

6 
2 

t 

24 
10 
.» 

|  From  +  BO'to—  5» 
!•  From  +  500  to—  12« 

f-  From  +  500  to  —  18* 

Sodium   nitrate  ! 
Nitric  acid,  diluted...1 

Sod  i  u  m    carbonate  .  '.  '.  •'.• 
Water    

[  From  +  60"  to—  3° 
t  From+50°  to—  7° 

Snow  or  pounded  Ice. 
Sodium   chloride.  ...-., 

Snow    

12 
6 
6 

8 

(•  From  4-  50"  to—  25» 
[  From  +  320  to—  23" 

Sodium    phosphate.-.  .  . 
Nitric  acid,  diluted... 
Sodium    sulphate  
Sulphuric  acid,  diluted. 
Sodium    sulphate  . 
Ammonium    chloride..' 
Potassium    nitrate  
Nitric  acid,  diluted... 
Sodium     sulphate  

[  From  +  50"  to  —  12° 
1  From  +  50"  to-t-3° 

f-  From-)-  50°  to—  10° 

Hydrochloric  '  acid.'  '.  '.  '. 
Snow  '  '.;..;  
Nitric  arid,  diluted.  .  . 
Snow  
Calcium    chloride..... 
Snow    ;  
Calcium  chloride,  cryst 
Snow    ..........  

5 
4 

4 

5 
2 

1  From  +  32°  to  —  27" 
|  From  +  320  to—  30" 
[  From  +  32°  to—  40° 
£  From-K32°  to  —  50° 

Nitric  acid,   diluted... 

1        om+60    t0~4°J 

Potash     ..-..;.  

4 

In  India  it  has  been  the  custom  from  ancient  times  to  make  ice 
by  the  quick  evaporation  of  water,  for  which  purpose  the  Indian 
puts  flat  dishes  filled  one-half  inch  with  water  in  a  box  twenty 
inches  deep  filled  with  straw.  In  dry  nights  part  of  the  water 
evaporates,  and  being  well  insulated  against  the  outer  air,  causes 
the  rest  of  the  water  to  freeze.  The  Compression  and  Absorption 
Machines  are  based  on  this  principle  of  evaporation. 

Ice  made  under  vacuum  was  first  done  by  Leslie,  born  1766,  at 
Largo,  in  Scotland.  Leslie  placed1  a  shallow  dish  filled  with  con- 
centrated sulphuric  acid,  and  a  few  inches  above  that  a  small 
glass  dish  with  water  under  the  receptacle  of  an  air  pump.  Under 
the  vacuum  water  vapors  were  formed,  which,  however,  were 
quickly  absorbed  by  the  acid,  so  that  the  evaporation  of  the  water 
proceeded  very  rapidly.  Through  this  quick  evaporation  on  the 
surface  of  the  water  the  heat  of  the  water  below  was  removed, 
until  it  was  frozen.  This  is  the  principle  of  the  Vacuum  Machine. 

At  the  beginning  of  the  last  century  Hutton  constructed  a  spe- 
cial machine  in  which  compressed  air  was  cooled  and  allowed  to 
expand.  He  obtained  in  this  way  such  low  temperatures  that  al- 
cohol was  made  to  freeze.  This  is  the  principle  of  the  Cold  Air 
Machine. 

These  different  methods  of  producing  cold  have  passed  through 
various  stages  of  development  and  have  led  to  constructions  of 
types  of  machines,  of  which  the  compression  machine  has  become 
the  most  prominent  one.  A  description  of  these  systems  will  b« 
given  in  the  following  order  : 

A.  Cold  Air  Machines.  C.  Absorption   Machines. 

B.  Vacuum   Machines.  D.  Compression   Machines. 


Cold  Air  Machines 

The  cold  air  machine  has  long  been  regarded  as  a  thing  of  the 
past  on  account  of  its  low  efficiency  and  enormous  size,  and  no 
machine  of  this  type  can  be  found  any  more  in  use  on  terra 
firma.  But,  strange  to  say,  the  cold"  air  machine  is  still  being 
built  and  has  been  installed  in  a  large  number  of  vessels.  The 
specifications  for  bids  for  several  U.  S.  warships  provide  that  the 
refrigerating  apparatus  shall  be  of  the  "Cold  Air  Machine"  type. 

Principle  of  Cold  Air  Machine. — When  air  is  compressed  in  a 
cylinder  by  mechanical  means,  its  temperature  rises.  The  heat  of 
compression  can  be  removed  by  injecting  a  spray  of  cold  water 
into  the  cylinder  or  by  passing  the  compressed  air  through  a  heat 
exchanger,  where  the  temperature  of  the  air  will  be  lowered  to 
nearly  that  of  the  cooling  water. 

When  the  air  is  now  allowed  to  expand  while  doing  work  in 
an  air  engine,  the  temperature  will  be  reduced  considerably  helow 


Engine 


FIG.    2— DIAGRAM    OF    COLD    AIR    MACHINE. 

the  initial  temperature  and1  the  expanding  air  is  capable  of  absorb- 
ing the  iieat  of  the  rooms  to  be  cooled.  For  example :  air  of 
68°  F.  under  atmospheric  pressure  will  be  heated  up  to  185°  -  F. 
when  subjected  to  a  pressure  of  two  atmospheres.  If  we  cool  this 
hot  air  down  to  about  86°  F.  by  means  of  cooling  water  and  let 
it  then  expand  to  its  initial  pressure,  its  temperature  will  be  low- 
ered to  13°  below  zoro.  After  the  air  has  done  the  work  of  cooling 
It  may  reenter  the  compressor,  thus  performing  a  continuous  cycle 
of  operation. 

This  operation  is  illustrated  in  Fig.  2. 

The  air  enters  the  compressor,  is  compressed  and  forced  through 
a  cooling  coil  submerged  in  cold  water,  where  the  heat  of  com- 
pression is  removed.  So  cooled,  it  enters  the  expand'er.  By  ex- 
panding, its  temperature  is  again  lowered  and  the  now  cold  air  is 
discharged  into  the  rooms  to  be  cooled. 

Historical  Facts. — In  1850  Dr.  Gorrie,  an  American,  constructed 
the  first  cold  air  machine.  In  his  machine  the  heat  of  compression 
was  removed  by  a  spray  of  cold  water  which  was  injected  into 


COLD  AIR  MACHINES. 


the  compressor.  By  expanding  the  cooled  air  a  second  spray  of 
water  was  turned  into  ice. 

A  similar  machine  was  constructed  two  years  later  by  Nesmond1. 
The  compressor  was  provided  with  a  water  jacket  and  the  air  was 
compressed  to  twenty  atmospheres.  In  a  second  cylinder  the  air 
was  allowed  to  expand,  whereby  liquids  were  cooled  or  water  was 
frozen. 

About  this  time  the  Windhausen  cold  air  machine  was  brought 
into  the  market  and  met  with  sojne  success.  About  one  hundred 
of  these  machines  were  built  and  several  were  in  active  operation 
up  to  the  year  1883. 

The  Bell-Coleman  machine  found  undoubtedly  the  largest  market, 
although  the  machine  did  not  differ  in  principle  from  Windhausen's 
design,  but  it  was  superior  in  the  construction. 

Of  later  constructions  we  only  mention  those  by  Menck  and  Ham- 
brock,  Lightfoot,  Haslam  Foundry  Co.,  and  the  Leicester  Allen 
machine. 

Quite  a  number  of  government  vessels,  private  yachts  and  steam- 
ers plying  in  South  American  waters  are  fitted  with  this  latter 
type  of  machine. 

The  "Allen"  Machine. 

The  Allen  cold  air  machine,  Fig.  3,  is  working  on  a  continuous 
cycle  of  operation.  The  air  is  taken  in  by  the  air  compressor  B, 
under  60  to  70  pounds  pressure  and  compressed  to  210  to  240 
pounds.  The  hot  air  is  passed  through  a  copper  coil  C  immersed* 


FIG.    3— DIAGRAM    OF    ALLEN    MACHINE. 

in    circulating    cold   water,    where    the    temperature    is    reduced    to 
nearly  that  of  the  water. 

The  now  cooled  air  enters  the  valve-chest  of  the  expander  D, 
which  is  constructed  like  a  steam  engine  with  a  cut  off  valve. 
The  valves  admit  the  highly  compressed  air  upon  the  piston  to  a 
certain  point  of  the  stroke  and  then  shut  it  off.  The  piston  con- 
tinues to  travel  to  the  end  of  the  stroke  under  the  expanding  force 
of  the  compressed  air,  assisting  in  this  way  the  engine  in  doing  the 
work  of  compression. 


i8  COLD  AIR  MACHINES. 

The  result  of  the  expansion  is  a  very  low  temperature  of  the  air 
at  the  end  of  the  stroke.  By  the  return  stroke  of  the  piston  the 
air  is  pushed  out  to  such  places  as  are  to  be  refrigerated. 

On  its  way  to  the  ice-making  box  the  air  passes  through  a  trap, 
where  the  oil  is  separated1  which  is  used  in  the  compressor  and 
expanded.  The  trap  contains  a  steam  jacket  in  order  to  melt  the 
frozen  contents  when  they  are  to  be  blown  out. 

Pump  F  circulates  the  cooling  water  through  the  cooling  tank 
and  through  the  water  jacket  around  the  compressor  B. 

A  small  air  compressing  pump,  G,  takes  air  from  the  atmosphere 
and  charges  the  system  with  the  required  air  pressure,  which  it 
maintains. 

This  air  contains  the  usual  atmospheric  moisture  and  to  expel 
this  the  air  is  first  forced  through  the  trap  H,  where  the  air  is 
cooled  by  coming  in  close  contact  with  the  cold  head  of  the  reser- 
voir. It  is  claimed  that  about  80  per  cent  of  the  moisture  is  in 
this  way  deposited  out  of  the  air  and  drained  off  by  pet-cocks. 
This  is  of  great  importance,  as  the  large  amounts  of  latent  heat 
in  the  water  vapor  would  produce  serious  losses  in  the  result  of 
the  machine  if  the  air  contained  water,  this  being  subject  to  the 
heating  and  freezing  processes  which  occur  in  the  machine. 

By  comparing  the  cold1  air  machine  with  compression  machines, 
it  is  evident  that  machines  which  do  not  liquefy  the  refrigerating 
medium  cannot  be  as  economical  as  those  which  do.  The  com- 
pression and  expansion  cylinders  of  the  cold  air  machine  have  to 
be  very  large,  which  increases  the  friction  considerably.  Besides 
this  there  is  excessive  clearance  and  this  together  with  the  unavoid- 
able moisture  contained  in  the  air  reduces  the  actual  efficiency  to 
less  than  33  per  cent  of  the  theoretical  efficiency. 

The  reason  for  still  using  the  cold  air  machine  on  board  ship 
is  all  and  alone  the  harmless  character  of  the  refrigerating  medium 
air. 

NOTES  ON  COLD  AIR  MACHINES: 


Vacuum   Machines 


The  vacuum  machine  is,  strictly  speaking,  based  on  the  same 
principle  as  the  absorption  machine,  which  we  will  discuss  in  our 
next  article.  Water  is  the  evaporating  medium  and  sulphuric  acid 
is  used  for  absorbing  the  vapors. 

Principle  of  Vacuum  Machine. — The  evaporation  of  the  water 
at  a  low  temperature  in  order  to  produce  refrigeration  is  brought 
about  by  forming  a  vacuum  by  means  of  a  vacuum  pump.  Such  a 
vacuum  is  now  produced  in  a  closed  vessel.  In  this  the  water  is 
injected,  part  of  which  quickly  evaporates,  whereby  the  'necessary 
latent  heat  is  removed  from  the  remaining  water,  which  will  be 
cooled  and  finally  frozen.  Theoretically  about  six  times  the  amount 
of  water  can  thus  be  frozen  by  the  evaporation  of  one  part  of 
water,  as  the  latent  heat  of  the  water  is  about  940,  that  is,  about 
six  times  the  latent  heat  of  ice,  viz.,  142. 

If  the  vacuum  should  be  maintained  solely  by  a  pump,  this 
pump  would  have  to  be  of  an  enormous  size  on  account  of  the 
low  tension  of  the  water  vapor  at  the  temperature  of  the  refrig- 
erator. In  ordter  to  avoid  excessively  large  pumps  an  absorbent 
was  looked  for  to  release  the  work  of  the  air  pump,  and  this  has 
led  to  the  introduction  of  sulphuric  acid,  by  which  the  vapors  are 
quickly  absorbed  and  removed  by  the  air  pump. 

The  acid  in  the  course  of  time  becomes  weak  and  has  to  be 
concentrated  again  by  distillation. 

The  operation  is  illustrated  in  Fig.  4.  The  vacuum  pump  is  con- 
nected to  the  absorber,  a  long  cylindrical  vessel  filled  to  two- 


Alr  Punp 


FIG.    4— DIAGRAM    OF    VACUUM    MACHINE. 

thirds  with  concentrated  sulphuric  acid,  which  is  kept  in  motion 
by  paddles  to  facilitate  the  absorption  of  the  water  vapors  coming 
from  the  water.  The  absorber  is  encased!  in  a  cold  water  jacket. 
In  the  cooler,  which  is  well  insulated,  the  refrigerating  work  takes 
place,  whereupon  it  is  connected  to  coils  through  which  the  cold 
liquid  circulates. 

The  other  apparatus  shown  in  the  illustration  serves  for  the 
concentration  of  the  sulphuric  acid.  The  cold  weak  acid  Is 
pumped  through  an  exchanger  into  the  distiller,  where  part  of  the 
absorbed  water  is  evaporated  and  removed  by  a  small  air  pump. 
The  strong  acid  leaves  at  the  bottom  and  flows  through  the  still 
back  to  the  distiller  in  a  superheated  state.  When  concentrated 
the  acid  leaves  at  the  highest  points,  parts  with  its  heat  and  re- 
enters  the  absorber. 

Historical  facts. — In  1810  Leslie  constructed  a  small  vacuum 
machine.  He  was  followed1  by  quite  a  number  of  others,  among 


20 


VACUUM   MACHINES. 


whom  was  Carre,  whose  machine  was  exhibited  at  the  World's  Fair 
in  Paris  in  1867.  Windhausen  was  the  first  to  build  a  vacuum 
machine  in  Germany  11878).  His  machine  is  illustrated  in  diagra- 
matic  form  in  Fig.  4.  The  vacuum  maintained  by  the  pump  is 
1-1500  atm.  =  1-50  inch  .abs.  press. 

Of  later  inventions  those  by  Lange,  Southby  and  Blyth  and 
Patten  may  be  mentioned. 

The  tatter  type  is  of  American  origin  and  of  recent  date. 

Patten  Vacuum  Machine. 

The  apparatus  starts  with  the  evaporator  or  freezing  chamber, 
as  it  is  called  here,  Fig.  5,  as  only  ice  is  produced.  A  vacuum 
of  about  30  inches  is  maintained  in  the  freezing  chamber  by  the 
air  pump,  which  will  cause  the  temperature  to  drop  down  to 


FIG.    5— DIAGRAM    OF    PATTEN    MACHINE. 

26°  F.  The  water,  generally  city  water,  which  has  previously  been 
filtered,  is  fed  by  a  hose  from  the  feed  water  tank  to  a  spraying 
device,  by  means  of  which  it  is  sprayed  against  the  ice-forms  in 
the  freezing  chamber.  By  means  of  special  mechanism  a  rotary 
reciprocating  motion  is  imparted  to  the  sprayer.  In  this  way 
cylinders  of  ice  are  formed,  having  an  outside  diameter  of  six  to 
eight  feet,  and  a  height  of  four  to  eight  feet.  The  thickness  may 
be,  of  course,  varied,  and  depends  on  the  quantity  of  water  fed.  A 
cylinder  of  about  seven  feet  outside  diameter  and  thirteen  inches 
thick,  having  a  length  of  three  feet  and  over,  weighs  about  3,200 
pounds  and  takes  about  one  hour  to  freeze. 

When  harvesting  the  ice,  the  cover  is  raised  and  the  cylinder  is 
withdrawn  from  the  freezing  chamber  and  transferred  to  the  cut- 
ting table,  where  it  is  reduced  to  blocks  of  commercial  size. 

It  is  claimed  that  about  86  per  cent  of  the  water  is  instantly 
frozen  in  touching  the  sides  of  the  ice  forms.  The  other  14  per 
cent  of  vapor  from  the  freezing  chamber  are  led  to  the  absorber, 
where  they  come  in  contact  with  the  sulphuric  acid  which  is  trick- 
ling over  'lead  coils,  through  which  cold  water  is  circulated.  The 
vapors  are  drawn  through  the  absorber  by  means  of  the  vapor  ex- 
hauster, where  they  are  compressed  and  forced  into  a  large  pipe 
leading  to  the  vapor  condenser. 


VACUUM  MACHINES.  21 

The  weak  acid  J eaves  the  absorber  and  is  pumped  through  a 
d'ouble  pipe  heat-exchanger  in  counter  current,  where  it  takes  up 
part  of  the  heat  of  the  strong  acid  before  entering  the  concentrator. 
Steam  from  the  boiler  is  supplied  "to  the  lead-lined  steam  pipes  of 
the  concentrator  and  th£  weak  acid  of  about  45°  Beaume  is  con- 
verted to  strong  acid  of  about  60°  Beaume. 

The  strong  acid  leaves  the  concentrator,  gives  up  part  of  its 
heat  to  the  weak  acid  in  the  heat  exchanger  and  in  a  special  cooler 
receives  a  final  cooling,  sufficient  to  be  used  again  in  the  absorber. 

The  vacuum  in  the  concentrator  being  about  27  inches,,  the  over- 
flow of  the  condenser  must  have  a  head  of  at  least  thirty-three  feet 
above  the  hot  well. 

The  first  plant,  which  Patten  erected,  did  not  use  any  chemical 
absorber.  It  was  erected  in  Baltimore  at  a  cost  of  over  three 
hundred  thousand  dollars,  but  has  proved  a  failure.  Other  plants 
using  sulphuric  acid  have  successively  been  erected  in  Baltimore, 
New  York,  San  Francisco  and  Porto  Rico. 

There  are  many  reasons  why  the  vacuum  machine  is  preA'ented 
from  being  more  adapted.  The  ice  frozen  by  this  process  is  not 
transparent,  but  opaque  and  resembles  chalk.  The  vessels  and 
pipes  containing  the  sulphuric  acid  must  be  of  lead  or  lead-lined  on 
account  of  the  corrosive  properties  of  the  acid.  The  necessity  for 
distilling  the  sulphuric  acid  represents  one  of  the  principle  ex- 
penses, while  the  handling  of  this  liquid  is  of  considerable  incon- 
venience. These  reasons  besides  the  difficulties  to  keep  the  sys- 
tem perfectly  tight  will  necessarily  put  the  vacuum  machine  behind 
other  systems,  or  at  least  will  confine  its  use  to  special  cases. 

NOTE 8  ON  VACUUM  MACHINES: 


Absorption  Machines 

The  absorption  machine  is  operated  in  a  similar  manner  as  the 
vacuum  machine,  only  that  ammonia  is  used  instead  of  water. 
Ammonia  has  a  great  affinity  for  water,  so  much  in  fact  that  one 
part  of  water  at  32°  F.  will  absorb  about  1,000  parts  of  ammonia 
at  atmospheric  pressure.  This  fact  is  utilized  in  the  following 
way  : 

Principle  of  Absorption  Machine. — Liquid  ammonia  under  an 
average  pressure  of  150  Ibs.  per  square  inch  is  admitted  to  the  ex- 
pansion coils,  where  it  rapidly  evaporates.  In  doing  this  it  produces 
a  refrigerating  effect  equal  to  its  latent  heat  of  vaporization.  The 
expanded  gas  is  subjected  to  a  stream  of  cold  water  in  the  ab- 
sorber, where  it  is  quickly  absorbed,  forming  aqua  ammonia.  This 
liquor  is  pumped  through  a  heat  exchanger  into  the  liquor  still, 
commonly  called  the  generator,  where  it  is  heated  up  by  means 
of  steam  coils  and  the  ammonia  driven  off  as  gas.  The  hot  gas 
being  confined  produces  pressure  much  as  steam  does  in  a  boiler. 
It  passes  from  the  still  to  the  condenser,  where  it  is  reduced1  to  a 
liquid  again  under  the  influence  of  pressure  and  cold  water. 

The  weak  hot  liquor  leaves  at  the  bottom  of  the  still  and  gives 
up  part  of  its  heat  in  the  exchanger  to  the  incoming  strong  liquor, 
before  being  able  to  absorb  anew  the  ammonia  vapors  in  the 
absorber. 

Historical  Facts. — The  inventor  of  the  absorption  machine  with 
a  continuous  cycle  of  operation  is  F.  Carre,  of  Paris  (1860).  His 
machine  was  improved  by  many  others,  notably  Vass  and  Littman, 


FIG.   6 — PONTIFEX    (CARBONDALE)    ABSORPTION   MACHINE. 

Nicolle  and  Pontifex.  The  latter  type  is  of  English  origin,  but  is, 
with  slight  alterations,  extensively  built  in  this  country,  where  it 
has  become  one  of  the  leading  absorption  systems. 

Pontifex   (Carbondale)    Absorption  Machine. 

The  illustration,  Fig.  6,  shows  the  generator  with  the  analyzer 
and1  exchanger  mounted  on  top.  The  first  charge  of  aqua  ammonia 
is  placed  in  the  generator,  where  it  is  heated  by  means  of  steam 


ABSORPTION  MACHINES. 


coils  in  the  usual  manner.  The  liberated  gas  passes  upward 
through  the  analyzer  where  some  of  the  water  still  left  in  suspen- 
sion in  the  gas  is  removed  by  a  series  of  baffle  plates.  Thence 
the  gas  enters  the  lower  coil  of  the  rectifier,  where  the  remaining 
water  is  condtensed,  much  in  the  same  way,  as  ammonia  is  liquefied 
in  the  De  La  Vergne  counter  current  ammonia  condenser.  The 
condensed  water  collects  in  a  manifold  and  returns  automatically 
to  the  generator. 

Thence  the  gas  passes  to  the  condenser,  where  it  is  liquefied. 
The  condenser  serves  also  as  a  liquid  receiver,  from  where  the 
liquid  is  fed  to  the  expansion  coils  in  the  brine  cooler. 

The  expanding  gas  is  absorbed  in  the  absorber  by '  the  weak 
liquor  coming  from  the  exchanger  and  the  resulting  strong  liquor  is 
returned  by  the  ammonia  pump  through  the  coils  in  the  exchanger 
to  the  generator. 

Condenser,  cooler  and  absorber  are  of  the  coil  and  shell  type, 
the  coils  are  wound'  concentrically  and  project  through  stuffing 
boxes  in  the  heads  and  are  manifolded  outside  of  the  shells. 

Vogt  Absorption  Machine. 

The  generator,  Fig.  7,  consists  of  a  main  casting,  divided  into 
four  compartments,  communicating  with  each  other,  and  four 
horizontal  pipes,  connected  to  the  main  casting,  which  contain  the 


*.„„  I. 


FIG.  7— VOGT  ABSORPTION  MACHINE. 

steam  heating  coils.  On  top  of  the  main  casting  is  mounted  a 
stand  pipe  containing  an  analyzer  and  rectifying  coil  for  dry- 
ing the  gas  before  leaving  the  still.  The  strong  liquor  is  admitted1 
to  the  top  of  the  stand  pipe,  passes  through  the  rectifying  coils 
and  analyzer  to  the  upper  compartment,  flowing  thence  over  the 
steam  coil  in  the  horizontal  pipes  from  one  to  the  other  until  the 
lower  compartment  is  reached. 

The  gas  generated  passes  through  the  opening  in  each  compart- 
ment to  the  stand  pipe,  where  the  moisture  is  deposited,  and  the 
dry  gas  passes  to  the  condenser,  which  is  of  the  atmospheric  hori- 
zontal zig-zag  coil  pattern. 

The  absorber  is  constructed  like  an  upright  tubular  boiler  open 
at  the  top.  Tubes  are  distributed  uniformly  and  arranged1  in  such 


24  ABSORPTION  MACHINES. 

manner  that  they  can  be  cleaned  while  the  machine  is  in  operation. 
The  cooling  water  enters  at  the  bottom  and  discharges  at  the  top! 
The  return  gas  from  the  expansion  coils  enters  at  the  bottom  and 
the  weak  liquor  at  the  top,  the  flow  of  the  latter  being  controlled 
by  an  automatic  regulator. 

The  ammonia  pump  is  of  the  double-acting  horizontal  fly-wheel 
pattern,  its  speed  is  25  revolutions  per  minute. 

The  exchanger  is  of  the  double  pipe  pattern.  The  strong  liquor 
enters  at  the  bottom,  while  the  weak  liquor  from  the  still  enters 
the  exchanger  at  the  top. 

Management  of  Absorption  Machine. 

The  first  thing  to  be  looked  after  in  a  new  plant  is  that  the 
apparatus  is  thoroughly  freed  from  air  before  it  is  charged  and 
that  it  is  properly  tested.  The  manufacturers  are  generally  sup- 
posed to  do  this,  but  even  if  they  do,  the  process  should  be  care- 
fully looked  after  by  the  engineer  in  order  to  avoid  complications. 
Two  ways  are  recommended  for  forcing  out  the  air,  the  most  effect- 
ive of  which  is  to  use  a  vacuum  pump.  If  the  pump  is  not  avail- 
able, the  apparatus  may  be  filled  with  steam,  all  valves  being  open, 
one  being  open  to  the  atmosphere.  The  steam  forces  the  air  out 
and  then  when  the  valve  is  closed  and  the  machine  cools  down, 
the  steam  condenses,  leaving  a  vacuum  in  the  apparatus.  The 
pumping  method  is  much  more  desirable,  since  the  steam  method 
sometimes  softens  the  joints,  if  they  are  made  up  with  rubber  es- 
pecially, and  it  is  seldom  that  the  boiler  pump  is  not  available. 

When  the  air  has  been  expelled,  the  apparatus  is  ready  to  re- 
ceive the  ammonia  and  the  charge  pipe  is  connected  to  a  drum  of 
ammonia  and  then  with  another  until  the  ammonia  ceases  to  flow 
in  because  the  vacuum  has  been  destroyed,  as  shown  by  the  vacuum 
gauge.  Nearly  all  the  ammonia  can  be  put  in  in  this  way,  but  an 
amount  nearly  sufficient  to  make  up  the  proper  charge  will  be  put 
in  by  the  ammonia  pump.  In  making  the  connections  to  the  am- 
monia drums  and  to  the  pump,  particular  care  must  he  taken  to 
not  allow  any  air  to  enter  the  machine  along  with  the  ammonia. 
The  ammonia  is  now  warmed  up  by  allowing  steam  to  flow 
through  the  coils  of  the  heater,  and  this  is  continued  until  the. 
pressure  on  the  system  rises  to  about  100  pounds  in  most  cases. 
A  piece  of  hose  is  then  attached  to  the  purge  cock,  which  1s 
opened',  and  the  end  of  the  hose  placed  in  some  vessel  containing 
water.  This  allows  any  remaining  air  to  come  out,  appearing 
in  the  form  of  bubbles  on  the  surface  of  the  water,  but  preventing 
any  flow  of  the  ammonia.  The  condensing  water  is  then  turned  on, 
and  also  the  steam,  until  the  liquid  ammonia  shows  in  the  gauge. 
Then  turn  on  the  cooling  water  wherever  it  is  used  and  let  the 
steam  into  the  generator  coils,  and  open  up  the  connection  to  let 
the  poor  liquor  into  the  absorber.  When  the  liquid  shows  in  the 
receiver  gauge,  open  up  the  expansion  valve  a  little  and'  the  valve 
on  the  pipe  between  absorber  and  cooler.  The  ammonia  -pump 
will  have  to  be  started  directly,  if  everything  works  all  right.  If 
air  develops,  it  must  be  eliminated  through  the  purge  cock  on 
the  absorber.  If  insufficient  pressure  develops,  the  charge  must  be 
increased  by  connecting  a  drum  of  liquid  ammonia  to  the  cooler 
and  allowing  it  to  flow  in.  Before  doing  this  the  expansion  valve 
should  be  shut. 

The  ammonia  pump  should  be  lower  than  the  supply  when 
pumping  ammonia.  The  proportionate  strength  of  the  weak  to  the 
strong  liquor  should  be  about  17  to  28.  When  this  is  not  the  case 
it  is  probably  due  to  leaks. 

Ammonia  will  cause  the  rubber  packing  on  pump  rods  to  swell, 
therefore  the  glands  must  not  be  screwed  down  too  tight. 

"Priming"  has  been  a  frequent  cause  of  shut-downs.  This  is  a 
case  of  all  the  ammonia  going  over  into  the  condenser,  including  the 


ABSORPTION  MACHINES.  25 

aqua  ammonia.  It  may  even  get  into  the  expansion  coils  if  they 
are  not  protected  by  a  check  valve.  This  is  indicated  by  the 
height  of  the  liquid  in  the  still,  by  a  drop  in  pressure  on  the 
cooler,  and  the  melting  off  of  the  ice  on  the  expansion  valve  air 
pipe.  The  liquor  in  the  still  should  always  cover  the  steam  coils. 
The  "boiling  over"  may  not  extend  further  than  from  the  generator 
to  the  absorber,  but  may  extend  to  the  condenser,  as  stated  above. 
If  the  liquid  is  at  the  right  level  in  the  liquid  receiver,  the  proper 
level  is  likely  to  be  maintained'  in  the  generator  unless  too  much 
is  coming  from  the  absorber.  The  pressure  behind  the  expansion 
valve  should  maintain  the  proper  height  of  liquid  in  the  generator. 
To  provide  against  this  trouble,  a  valve  is  placed  on  the  poor  liquor 
line  at  the  absorber,  so  that  the  ammonia  can  be  kept  at  the 
proper  height.  When  the  ammonia  has  gone  over  into  the  expan- 
sion coils,  the  expansion  valve  can  be  almost  closed  and  a  vacuum 
pumped  on  the  absorber.  The  gas  is  then  blown  through  the  coils 
and  this  will  generally  take  it  all  back  to  the  absorber.  This 
trouble  may  be  avoided  when  the  expansion  coils  are  built  In 
sections  connected  to  manifolds  with  separate  valves.  In  such 
case  each  section  can  be  cleared  separately. 

James  Cooper,  in  Power,  recommends  in  a  case  of  priming  that 
the  pump  be  kept  going  to  get  a  good  vacuum  on  the  absorber. 
Then  to  open  the  expansion  valve  so  as  to  get  all  the  weak  liquor 
out  of  the  receiver  and  condenser  into  the  cooler,  and1  if  the  pres- 
sure is  still  below  that  of  the  absorber,  and  they  both  show  a 
vacuum  at  this  time,  shut  the  expansion  valve  and  open  the  anhy- 
drous charging  valve.  This  will  let  the  air  run  in  from  outside 
and  cause  the  cooler  to  show  atmospheric  pressure,  which  will  be 
greater  than  the  pressure  in  the  absorber,  and  then  be  pumped  to 
the  generator  again.  This  operation  to  be  kept  up  until  the  machine 
is  normal.  The  cause  of  this  condition  may  be  that  the  charge  is 
too  weak  or  the  machine  is  working  too  fast  and  the  generator  is 
dirty.  The  weak  liquor  will  have  to  go  through  the  purge  line  at 
the  bottom  of  the  cooler,  and  to  keep  a  greater  pressure  on  the 
cooler  than  on.  the  absorber  the  gas  .  line  will  have  to  be  closed 
between  the  cooler  and  the  absorber.  This  will  force  the  liquid  out 
faster.  This  is  recommended  in  case  there  is  no  pipe  from  the 
receiver  to  the  cooler. 

The  management  of  an  absorption  system  mainly  depends  on  the 
regulation  of  pressures  and  temperatures.  If,  for  instance,  there 
is  too  high  a  pressure  in  the  absorber  and  consequently  too  high 
a  temperature  in  the  cooler,  the  cause  may  be  either  too  little  or 
too  warm  cooling  water  or  too  much  liquid  in  the  system  or  the 
presence  of  foreign  gases  and  air  in  the  system.  These  latter  are 
eliminated  through  the  purge  cock  at  the  top  of  the  absorber. 

One  reason  for  the  failure  of  an  absorption  machine  not  to 
work  to  its  full  capacity  at  times  is  because  the  steam  coils  in  the 
generator  become  air  locked.  By  putting  on  a  small  vacuum 
pump  the  efficiency  of  the  still  may  he  considerably  increased. 

Leaks  in  rectifying  pans  are  indicated  when  a  sample  of  liquid 
from  the  liquid  receiver  shows  a  high  percentage  of  water. 

iA  leak  in  the  exchanger  is  indicated  by  the  cooling  of  the  pipe 
connecting  the  exchanger  with  the  weak  liquor  at  the  bottom  of 
the  still.  There  is  also  likely  to  be  a  hissing  sound  produced  by 
the  leak.  The  leak  can  usually  be  traced  by  noting  the  tem- 
perature of  the  pipe. 
Economy  of  Absorption  Machine. 

The  absorption  machine,  once  a  favorite,  was  largely  replaced1  by 
the  compression  system,  but  is  now  coming  into  considerable  use 
under  certain  conditions.  The  economy  has  been  greatly  increased 
since  the  manufacturers  are  able  to  produce  an  almost  perfect 
anhydrous  gas  from  the  generator  and  since  it  is  possible  to  use 


26  ABSORPTION  MACHINES. 

the  exhaust  steam  from  the  auxiliary  machinery  to  evaporate  the 
ammonia  in  the  generator. 

According  to  Torrance,  in  a  paper  before  the  Eastern  Ice 
Association  the  best  absorption  machines  of  the  present  time  use, 
in  the  generator,  about  30  pounds  of  steam  per  hour  per  ton  of 
refrigerating  effect  under  can  ice  conditions,  some  use  35,  and 
many  machines  recently  erected,  but  of  poor  design,  use  50  pounds 
or  more.  A  theoretically  perfect  absorption  machine  would  require 
for  the  generator  about  24  pounds  per  hour  per  ton  with  10  pound's 
steam  pressure  for  can  ice  conditions,  this  quantity  being  practi- 
cally independent  of  the  temperature  of  the  condensing  water. 

If  a  machine  uses  26  pounds  of  steam  per  hour  per  ton,  then  we 
could  freeze  ice  on  the  can  system  out  of  60°  F.  raw  water  with 
the  following  steam  consumption  per  hour  per  ton  of  ice  : 

POUNDS. 

Cooling  water  from  60°  to  32°  F 5 

Freezing  water  at  32°   F 26 

Cooling  ice  from  32°  to  15°  F 1.5 

Cooling  300-lb.  cans  from  60°  to  15°  F 2 

Radiation  and  losses    7.3 

Meltage  loss  3%  of  total 1.2 


Total  pounds  steam  per  hour 41.2 

A  horizontal  tubular  boiler,  semi-bituminous  coal,  under  careful 
firing  will  evaporate  10.3  pounds  of  water  per  pound  of  coal  from 
and  at  212°  or  10  pounds  into  steam  at  70  pounds  pressure  with 
212°  feed  water.  Hence,  coal  per  hour  would  be  4.12  pounds  per 
ton  of  ice,  or  99  pounds  per  day  per  ton  of  ice,  or  20  pounds  of  ice 
per  pound  of  coal. 

Practical  Ice  Plants  of  the  Present. — If  we  have  a  horizontal 
tubular  boiler  with  above  mentioned  evaporation,  from  feed  water 
at  212°  (which  is  quite  easily  obtained  with  a  slight  pressure  on 
the  exhaust),  we  should  be  able  to  make  10  pounds  of  ice  per 
pound  of  coal  provided  we  have  no  losses. 

If  the  plant  is  designed  properly  there  would  be  five  losses. 

(1)  Condensed   steam    caused   by    radiation    of   pipes    and1  pump 
cylinders  which  forms  an  emulsion  with  the  lubricating  oil  and  is 
trapped  out  in  the  oil  separator.     There  is  no  cut-off  on  these  pumps 
and  the  condensation  is  practically  limited  to  the  radiation  of  the 
exposed  surfaces  and  should  not  exceed  5  per  cent. 

(2)  Direct  leakage  of  steam  from  stuffing  boxes  and  joints.     This 
is  too  small  to  be  considered. 

(3)  Reboiling    loss.      The    condensed    steam    from   the    generator 
discharges  at  10  pounds  pressure  into  the  reboiler  and  immediately 
drops  in  temperature  from  240°  to  212°  F.,  causing  1  per  cent  to 
evaporate,  which  produces  all  the   reboiling  generally  necessary. 

(4)  Skimming    loss    under    these    conditions    should    not    exceed 
%  per  cent. 

(5)  Meltage  at  ice  cans,  3  per  cent. 
Total  losses  9%  per  cent. 

The  boiler  evaporation  being  10 :1  under  the  above  conditions 
this  would  ma"ke  the  economy  9  pounds  of  ice  per  pound  of  coal, 
which  is  about  the  result  actually  obtained  in  practice. 

NOTES  ON  ABSORPTION  MACHINES: 


ABSORPTION  MACHINES.  27 


Compression  Machines 

Principle  of  Compression  Machines. — The  compression  machine 
is  based  on  the  evaporation  of  liquids,  which  have  a  low  boiling 
point.  The  latent  heat  of  evaporation  represents  the  amount  of 
cold  that  can  be  produced  in  precisely  the  same  way  as  in  the  ab- 
sorption machine.  The  former  system,  however,  differs  from  the 
latter  in  so  far,  as  the  expanded  gas  after  having  done  the  work 
of  cooling  in  the  expansion  coil,  instead  of  being  absorbed,  enters 
the  suction  of  a  strong  air  compressor,  where  the  necessary  pres- 
sure is  applied  to  reduce  the  gas  to  a  liquid  again. 

The  principal  refrigerating  media  used  in  the  compression  ma- 
chine are  ether,  sulphur  dioxide,  carbonic  acid  and  ammonia. 

The  systems  are  all  based  on  the  same  principle  and  the  machines 
differ  only  in  points  of  construction. 

A  compression  machine  comprises  the  three  fundamental  parts : 

(1)  The  compressor,  which  withdraws  the  gas  from  the  refrig- 
erator coil  and  compresses  it  into  the  condenser. 

(2)  The  condenser,  where   the  heat  of  compression   is  removed 
by  cooling  water  and  the  gas  becomes  liquefied. 

(3)  The  refrifferator,  where  the  liquid  evaporates  into  a  gas  and 
does  the  refrigerating  work. 

These  principles  are  generally  the  same  for  the  various  liquids 
employed,  amplified,  of  course,  by  different  appliances  for  lubricat- 
ing the  piston  and  stuffing  box,  by  special  devices  for  separating  oil 
and  foreign  matters  from  the  medium,  etc. 

Ether  Machines. 

In  1834,  Perkins  employed  already  the  vapors  of  Ether  (Ethyl 
Ether)  whose  boiling  point  is  at  above  100  degs.  F.,  for  his  com- 
pression machines  and  the  construction  and  arrangement  of  his 
system  were  similar  to  the  modern  compression  machines. 

It  consisted  principally  of  a  compressor,  refrigerator  and  con- 
denser with  regulating  valve  between  the  two  last  mentioned. 

In  1867,  Teller  used!  first  Methyl  Ether,  which  has  a  lower  boil- 
ing point,  and  in  1878  Vincent  employed  Chlormethyl  Ether. 

Ether  machines  were  never  y^ery  popular,  chiefly  on  account  of 
their  great  danger  in  case  of  fire  and  the  relative  large  compressors, 
for  which  reason  we  do  not  want  to  go  any  deeper  into  the  con- 
structive details  of  this  type  of  machine. 

Sulphur  Dioxide  Machines. 

These  machines  have  lately  come  more  and  more  into  the  fore- 
ground. Though  the  latent  heat  of  the  medium  is  lower  than  am- 
monia besides  having  a  higher  boiling  point  which  requires  larger 
compressors,  this  machine  has  certain  advantages.  The  pressures 
corresponding  to  the  required  temperatures  are  low;  they  go  up  to 
sixty  pounds  at  the  highest  during  compression  and  down  to  seven 
to  fifteen  pounds  in  the  refrigerator. 

Lubrication  is  entirely  superfluous,  as  the  liquid  SO2  is  a  first- 
class  lubricating  medium.  Another  advantage  is  its  non-corrosive 
action  toward  metals,  which  allows  the  use  of  brass,  copper  and 
other  metals  besides  iron.  But  great  care  has  to  be  taken  to  main- 
tain tight  joints  as  any  leakage  might  produce  sulphuric  acid,  which 
would  become  detrimental  to  any  metal. 

Teltier  was  the  first  in  1865,  to  recognize  the  importance  of  sul- 
phur dioxide  as  a  refrigerating  medium,  and  in  1876,  Pictet  made 
use  of  the  same  in  his  machine.  His  machines  have  since  then 
been  built  extensively. 

The  principles  of  the  compression  machines  are  also  applied  to 
the  sulphur  dioxide  machines,  although  the  whole  arrangement  Is 


COMPRESSION  MACHINES.  29 

simpler,  as  the  apparatus  for  separating  the  oil  from  the  gas  and 
everything  herewith   connected  are  not  needed. 

Carbonic  Acid  Machines. 

Carbonic  acid  (CO2)  has  besides  ammonia  and  sulphur  dioxide 
found  the  greatest  use  in  compression  machines.  This  machine  was 
first  built  In  1883,  by  the  Maschinenfabrik  Augsburg,  but  became 
more  known  through  Windhaussen  in  1889,  who  succeeded  In  bring- 
ing an  efficient  design  in  the  market. 

In  his  machine  the  clearance  was  filled  out  with  glycerine.  This 
brought  some  disadvantages.  Part  of  the  glycerine  could  pass 
through  the  valves  into  the  pipes  and  apparatus  and  reduce  the 
efficiency.  This  loss  again  increased  the  clearance. 

Sedlacek  built  his  machine  so,  that  the  sealing  liquid  was  kept 
under  pressure  and  the  loss  made  up  automatically  by  a  small 
pump.  Later  constructions  have  done  away  with  glycerine  and1  use 
oil  instead. 

It  will  be  found  that  machines  working  with  dry  gas  are  capahle 
of  performing  a  refrigerating  duty  which  exceeds  that  of  the  wet 
system  by  about  ten  per  cent.  (Goosmann,  A.  S.  R.  E.  Trans., 
1906.)  When  manufacturers,  nevertheless,  adhere  to  the  wet  sys- 
tem in  preference,  it  is  simply  the  logical  outcome  of  practical 
considerations.  The  packing  of  the  piston  consists  of  leather  cups  ; 
fftis  material  does  not  withstand  temperatures  above  200°  F.  and 
in  order  to  keep  them  pliable,  it  is  necessary  to  remove  the  heat 
of  compression  by  means  of  wet  gases  from  the  evaporator.  Me- 
tallic packing  with  its  consequent  greater  piston  leakage  and  dry 
gas  compression,  offers  no  gain  in  comparison  with  the  wet  sys- 
tem and  its  slight  loss  of  evaporation  which  Is  offset  by  the  ad- 
vantage of  using  a  tight  piston  packed  with  cupped  leathers. 

The  fact  that  during  compression  the  gas  is  in  a  superheated 
state,  occasioning  considerable  changes  in  its  entropy  with  tem- 
peratures and1  pressures  above  the  critical,  explains  the  peculiarity 
that  the  refrigerating  work  of  this  system  does  not  cease  with 
high  condenser  temperatures. 

Constructional  Details. — The  cylinders  are  made  of  soft  forged 
steel,  as  it  seems  impossible,  here  as  well  as  in  England,  to  secure 
sound  castings  that  will  withstand  the  high  internal  pressures. 
These  cylinders  require  considerable  lathe  and  drill  work  for  the 
bore,  canals  and  other  openings.  When  finished,  however,  it  is 
hardly  necessary  to  subject  them  to  tests. 

The  bore  should  be  about  one-fourth  of  the  stroke,  for  instance, 
a  machine  of  20  tons  capacity  having  a  bore  of  four  inches  should 
have  a  stroke  not  less  than  sixteen  inches.  A  machine  of  five-inch 
bore  by  20-inch  stroke  will  easily  have  a  capacity  of  40  tons,  which 
shows  the  influence  of  a  slight  increase  in  the  size  upon  the 
capacity. 

A  long  piston  is  of  great  advantage.  The  relation  of  diameter 
and  length  of  piston  is  about  1 :2.5.  These  valves  are  usually 
placed  in  the  horizontal  position,  but  as  they  are  comparatively 
small  and  of  light  weight,  it  does  not  require  a  very  heavy  spring 
to  close  them.  The  discharge  valves  are  placed  vertically  and  are 
therefore  always  in  the  centrical  position.  The  area  of  the  dis- 
charge and  of  the  suction  valve  is  one-seventh  of  the  piston  area 
for  the  former  and  one-half  for  the  latter.  On  the  piston  rod 
end  two  suction  valves  are  frequently  used,  as  there  is  hardly 
sufficient  room  for  one  valve  having  the  required  area.  The  width 
of  the  seat  should  not  exceed  0.1  to  0.12  of  the  valve  disc  diameter, 
and1  an  angle  of  70°  to  90°  for  the  discharge  valve  seat  and  60° 
to  75°  for  the  suction  valve  are  considered  good  practice.  A  valve 
life  of  0.33  diameter  for  the  suction  valve  and  0.28  diameter  for 
the  discharge  valve  are  the  right  proportions.  A  spring  tension  of 


30  COMPRESSION  MACHINES. 

8  to  9  Ibs.  for  the  suction  valve  and  10  to  11  Ibs.  for  the  discharge 
valve  will  be  found  ample. 

The  most  essential  point  is  the  stuffing  box.  Owing  to  the  high 
internal  pressure,  as  well  as  to  the  comparatively  large  piston  rod, 
it  is  necessary  to  divide  the  stuffing  box  into  several  chambers, 
consisting  of  removable  lanterns,  which  are  so  arranged  that  the 
pressure  is  reduced  by  steps.  The  chamber  next  to  the  cylinder 
bore  takes  care  of  the  leakage ;  a  controlling  device  is  usually  con- 
nected to  this  chamber  by  means  of  which  the  gas  is  returned*  to 
the  suction  side  at  a  pressure  higher  than  that  of  the  evaporation 
and  lower  than  the  condenser  pressure.  The  next  chamber  is  kept 
under  oil  by  a  force  pump,  which  forces  the  oil  into  it  at  a  pres- 
sure slightly  above  that  of  the  suction.  An  oil  outlet,  controlled 
by  a  ball  valve,  leads  from  this  chamber  to  the  suction  canal  of 
the  compressor,  so  that  a  small  amount  of  oil  together  with  an 
occasional  bubble  of  gas  enters  the  compressor  at  this  point.  Gar- 
lock  or  any  other  soft  packing  is  used  at  the  outer  end  merely  as  a 
wiper  of  the  lubricating  material,  preventing  oil  leakage  at  that 
point. 

Leather  cups  are  used  almost  exclusively  as  the  packing  material, 
they  having  given  much  better  satisfaction  than  any  other  known 
method  of  packing.  In  packing  the  stuffing  box  with  this  material, 
the  glands  must  be  drawn  up  tight,  as  no  provision  for  expansion 
of  the  material  need  be  made  in  this  case  ;  only  the  outer  nut,  which 
holds  the  Garlock  packing  in  place,  is  left  comparatively  loose. 
The  life  time  of  this  packing  is  a  season  or  more  with  ordinary 
care.  A  trap  to  separate  the  oil  from  the  gas  is  connected  in  the 
discharge  pipe  between  compressor  and1  condenser. 

Safety  valves  are  always  used.  The  location  of  this  valve  on  the 
compressor  is  in  the  discharge  canal.  They  also  serve  the  pur- 
pose of  protecting  the  compressor  in  the  case  of  careless  starting, 
without  opening  the  delivery  stop  valve.  This  valve  is  usually 
provided  with  a  cast  iron  disc,  proportioned  to  break  at  a  pressure 
of  about  150  atmospheres. 

When  condenser  water  of  temperatures  above  74°  F.  is  used  it  is 
advisable  to  provide  a  special  liquid  cooler  for  the  purpose  of  reduc- 
ing .the  temperature  of  the  liquid  before  it  passes  the  expansion 
valve.  Submerged,  atmospheric  and  double-pipe  condensers  are  used1 ; 
the  customary  rules  prevail  regarding  the  surface  of  the  evaporator 
pipe,  with  this  difference,  that  the  evaporating  temperatures  may 
readily  be  dropped  much  below  zero  F.  without  changing  materially 
the  ratio  of  compression,  which  ordinarily  is  1  :3. 

While  it  is  true  that  the  theoretical  efficiency  of  the  carbonic 
acid  system  is  not  equal  to  that  of  the  ammonia  machine,  owing 
to  the  greater  percentage  which  the  specific  heat  of  the  liquid 
carbonic  acid  bears  to  the  latent  heat  of  evaporation,  yet  the  prac- 
tical efficiency  of  the  machine,  owing  to  compensating  features, 
makes  up  for  the  above  loss.  These  consist  in  less  piston  leakage, 
a  smaller  depression  of  the  suction  line,  and  slightly  smaller  losses 
through  clearance. 


Ammonia  Compression  Machines 


In    1870    Linde   built    the    first    ammonia    compression    machine, 
which  has  become  the  standard  for  modern  refrigerating  machines. 
About  the  same  time  Boyle  constructed  a  similar  machine. 
The  Linde  machine  in  its  principle  is  operated  on  the  compres- 


HEAD" 


g  —  "SAFETY 
COMPRESSOR. 


FIG. 


'LINDE." 


FIG.    10— "OIL" 
COMPRESSOR. 


sion  cycle,  which  we  have  described  above.  Almost  all  later  de- 
signers have  constructed  their  machines  after  the  Linde  and 
Boyle  patterns  with  slight  variation. 

The  leading  compressor  types  as  built  in  this  country  are 
illustrated  in.  Figs.  8  to  10,  and  may  be  briefly  enumerated  here. 

The  Linde  compressor,  Fig.  9,  is  worth  careful  study  by  both 
the  student  and  engineer,  as  it  is  a  good  example  of  how  efficiency 
may  be  combined  with  simplicity.  The  cylinder  is  one  plain 
cylindrical  bushing.  Both  heads,  holding  the  valves,  as  well  as 
the  piston,  are  turned  spherical  and  fit  snugly  against  each  other. 
There  is  hardly  any  clearance,  the  piston  at  extreme  end  of  the 


FIG.    11— "DB  LA  VERGNE"   COMPRESSION   SYSTEM. 


COMPRESSION  MACHINES. 


stroke  being  only  1-32  inch  from  the  cylinder  head.  The  com- 
pressor is  double-acting  and  may  be  horizontal  or  vertical. 

The  safety-head  compressor,  Fig.  8,  is  also  put  on  the  market 
by  a  great  number  of  builders. 

The  advantage  of  the  safety  head  is  the  security  it  guarantees 
against  the  breaking  of  the  head  in  case  of  accidental  breaking 
of  valves  or  any  other  part  of  the  machine,  as  well  as  an  over- 
charge of  liquid  ammonia  getting  in  the  compressor,  in  which 
case  the  head  lifts  and  allows  the  obstruction  to  pass  through. 

The  oil  compressor,  Fig.  10,  was,  some  ten  years  ago,  con- 
sidered the  foremost  machine  in  the  market,  and  is  still  one 
of  the  most  efficient  ones;  but  owing  to  its  expensive  construction 
it  is  only  built  when  there  is  a  special  demand  for  it. 

Cycle  of  Operation. 

The  cycle  of  operation  is  illustrated  in  Figs.  11  and  12. 
These  cuts  show  plainly  every  detail,  and  as  drawings  sometimes 
speak  plainer  than  words,  especially  to  the  trained  engineer,  we 
will  try  to  save  space  by  omitting  the  descriptions. 


^         - -        "•  •-    •  -    •'• 


FIG.   12—  "LINDE"   COMPRESSION   SYSTEM: 


Compressor 

Capacity  of  Compressor. 

The  refrigerating  capacity  of  a  compressor  per  minute  is  the 
product  of  the  number  of  cubic  feet  that  can  be  discharged  by 
the  compressor  per  minute  and  the  refrigerating  effect  of  one 
cubic  foot  of  gas.  Thus  we  have  to  consider  the  following  two 
points: 

1.  The  cuMo  capacity  of  the  compressor. 

2.  TJie  refrigerating  effect  of  the  medium  employed. 

Cubic  Capacity. 

The  theoretical  displacement  is  ascertained  by  multiplying  the 
piston  area  by  the  stroke,  and  the  number  of  revolutions  per 
minute,  and,  in  case  of  a  double-acting  compressor,  by  doubling 
the  result  (deduct  area  of  piston  rod). 

3.14d2 
C  =  2  -  In 

4 
where  d  =  dia.  of  piston,  1  =:  stroke,  n  =  number  of  rev.  p.  mln. 

The  actual  displacement  depends  on  the  efficiency  of  the  com- 
pressor. The  greater  the  ratio  of  compression,  the  greater  is  the 
loss  with  a  given  amount  of  clearance.  Assuming  a  condenser 
pressure  of  160  pounds  and  a  back  pressure  of  20  pounds,  or  a 
compression  ratio  of  1:8,  with  a  clearance  of  %  inch,  the  gas 
would  re-expand  from  160  pounds  to  20  pounds,  and  occupy  1 
inch  space,  before  fresh  gas  could  be  admitted  into  the  com- 
pressor. This  1  inch  would  be  deducted  from  the  effective  stroke 
and  by  assuming  a  compressor  having  a  10-inch  stroke,  would 
mean  a  loss  of  10  per  cent. 

Refrigerating  Effect  of  Medium. 

The  refrigerating  effect  of  1  cb.  ft.  of  gas  is  represented  by  the 
latent  heat  of  1  Ib.  of  gas,  divided  by  the  volume  of  1  lb.  of  gas. 

From  the  latent  heat,  however,  we  have  to  deduct  the  amount 
of  refrigeration,  which  is  required  to  reduce  the  temperature  of 
the  liquid  from  the  condenser  temperature  to  the  refrigerator 
temperature.  This  amount  is  the  difference  in  temp,  multiplied 
by  the  spec,  heat  of  the  medium. 

hi  -  (t  -  tx)  s 


v 

t  =  condens.  temp.,  ti  =  refr.  temp.,  s  =  spec,  heat  of  medium, 
hi  =  latent  heat  at  temp,  ti,  v  =  volume  of  1  lb.  of  gas  in  cub. 
ft.  at  refr.  temp.  (See  ammonia  table.) 

Example.  —  What    is    the    refr.    capacity    of    a    double-acting    am- 
monia compressor  9  X   15,  70  rev.  p.   min.,   temp,  in  refr.   =   0°, 
temp,  in  condenser  =  85°. 
By   assuming   an    efficiency    of    90%,    the    actual    displacement 

3.14  X  0.752 

would    be    2  -  X  1.25  X  70  X  0.9  =  69.3   cb.   ft.   p.   min. 
4 

555.5  —  (85  —  0)  1 
The  refr.  effect  per  cb.  ft.  =  --  =  52.3  units  p.  min. 

9.1 
Capacity  of  compressor  =  69.3  X  52.3  =  3624.4  units  per  min.,  or 

3624.4  X  60  X  24 
in  tons  of  refr.  =  --  =  18.4  tons  in  24  hrs. 

284,000 
Cubic  capacity  of  compressors  per  ton  per  min.  = 


=  4.18  cub.  ft. 


0.9  X  18.4 


34 


COMPRESSOR. 


REFRIGERATING  EFFECT  (B.  T.   U.)   OF  ONE  CU.   FT.  OF  AMMONIA 
GAS  PER  MIN. 


o  . 

£A 

1     Temperature  of  the  Liquid  in  Degrees  F. 

o 

*-  u 

11* 

65°       700/      75°       80J       85J       90°       95°      100       105 

2& 

§pu  £ 

Q. 

£~« 

Corresponding  Condenser  Pressure  (gauge).  Ibs.  per  sq.  in 

£•- 

<3j»3 

103       115       127       139       153       168       184       200       218 

H 

\ 

G.Pres. 

-27° 

1 

27.30 

27.01 

26.73 

"26.44 

26.16 

25.87 

25.59 

25.30 

25.02 

-20° 

4 

33.74 

33.40 

33.04 

32.70 

32.34 

31.99 

31.64 

31.30 

30.94 

6 

36.36 

36.48 

36.10 

35.72 

35.34 

34.96 

34.58 

34.20 

33.82 

-10° 

9 

42.28 

41.84 

41.41 

40.97 

40.54 

40.10 

39.67 

39.23 

38.80 

-  5° 

13 

48.31 

47.81 

47.32 

46.82 

46.33 

45.83 

45.34 

44.84 

44.35 

0° 

16 

54.88 

54.32 

53.76 

53.20 

52.64 

52.08 

51.52 

50.96 

50.40 

5° 

20 

61.50 

60.87 

60.25 

59.62 

59.00 

58.37 

57.75 

57.12. 

56.50 

10° 

24 

68.66 

67.97 

67.27 

66.58 

65.88 

65.19 

64.49 

63.80 

63.10 

15° 

28 

75.88 

75.12 

74.35 

73.59 

72.82 

72.06 

71.29 

70.53 

69.76 

20' 

33 

85,15 

84.30 

83.44 

82.59 

81.73 

80.88 

80.02 

79.17 

78.31 

25° 

39 

95.50 

94.54 

93.59 

92.63 

91.68 

90.72 

89.97 

88.81 

87.86 

30° 

45 

106.21 

105.15 

104.09 

103.03 

101.97 

100.91 

99.85 

98.79 

97.73 

35° 

51 

115.69 

114.54 

123.39 

112.24 

111.09 

109.94 

108.79 

107.64 

106.49 

CUBIC  CAPACITY  OF  COMPRESSOR   (PER  MIN.)   PER  TON  OF  REFR. 
(IN  24  HRS.) 


1- 

& 

Temperature  of  the  Gas  in  Degrees  F. 

2s 

IB 

65°       70°       75°       80;       85*       90°       95°      100°     105° 

*f 

£  e  a 

£Q 

o'fjS 

Corresponding  Condenser  Pressure  (gauge),  Ibs.  per  $q.  in. 

H 

UjH 

103       115       127       139      153       168       184      200      218 

-27° 

G.Pres. 
1 

7.22 

7.3 

7.37 

7.46 

7.54 

7.62 

7.70 

7.79 

7.88 

-20° 

4 

5.84 

5.9 

5.96 

6.03 

6.09 

6.16 

6.23 

6.30 

6.43 

-15° 

6 

5.35 

5.4 

5.46 

5.52 

5.58 

5.64 

5.70 

5.77 

5.83 

-10° 

9 

4.66 

4.73 

4.76 

4.81 

4.86 

4.91 

4.97 

5.05 

5.08 

-  5° 

13 

4.09 

4.12 

4.17 

4.21 

4.25 

4.30 

4.35 

4.40 

4.44 

O9 

16 

3.59 

3.63 

3.66 

3.70 

3.74 

3.78 

3.83 

3.87 

3.91 

5° 

20 

U20 

3.24 

3.27 

3.30 

3.34 

3.38 

3.41 

3.45 

3.49 

10° 

24 

2.87 

2.9 

2.93 

2.96 

2.99 

3.02 

3.06 

3.09 

3.12 

15° 

28 

2.59 

2.61 

2.65 

2.68 

2.71 

2.73 

2.76 

2.80 

2.82 

20° 

33 

2.31 

2.34 

236 

2.38 

2.41 

2.44 

2.46 

2.49 

2.51 

25° 

39 

2.06 

2.08 

2.10 

2.12 

2.15 

2.17 

2.20 

2.22 

2.2-4 

30° 

45 

1.85 

1.87 

1.89 

1.91 

1.93 

1.95 

1.97 

2.00 

2.01 

35° 

51 

1.70 

1.72 

1.74 

1.76 

177 

1.79 

1.81 

1.83 

1.85 

Horse  Power  Required. 

The  worfc  required  from  the  compressor  for  every  Ib.  of  liquid 
consists  in  lifting  the  latent  heat  through  the  range  of  refr.  temp. 
to  condens.  temp. 


W  = 


hi     (T  =  abs.  refr.  temp.  =ti  +  460) 


The   amount   of   liquid   per  minute   is  the  product  of  the  cubic 
capacity  and  the  weight  of  1  cb.  ft.  of  gas  at  refr.  temp. 
Example  continued  :    The  work   for   above  compressor   would1  be 
t  —  ti  85  X  555.5  X  69.3  X  0.11 

—  -  hi  Ci  a  =  --  =  782.5  units  per  min. 
T  460 


COMPRESSOR. 


35 


782.5  X  778 


=  18.5  H.  P. 


33,000 

The  actual  horse-power  required  to  operate  the  compressor  must 
necessarily  be  larger  on  account  of  the  friction  of  piston,  stuffing 
box,  etc.,  which  varies  with  the  size  of  the  compressor  and  the 
method  of  transmission  of  power.  For  safe  calculations  assume 
the  actual  horse-power  to  be  at  least  1.4  times  the  theoretical. 
18.5  X  1.4  =  rd.  26  h.  p. 

H.   P.   BASED  ON  27  LBg.   BACK  PRESS.   AND   156  LBS.  CONDENSING 

PRESS. 

Tons  refr.    ..      5    10    15    20    30    50    75    100    150    200    300    500 
H.    P 10     15    20    25    37    60    90    120    1-80    240    350    580 

HORSE   POWER   PER   CU.    FT.    OF    AMMONIA   PER   MINUTE. 
CONDENSER    PRESSURE    AND    TEMPERATURE. 


P 

0 

9 

P 

103 

"5 

127 

139 

153 

168 

184 

200 

218 
105' 

2661 
.2796 
.2971 

Te,, 

65" 

70' 

75° 

80° 

85° 

90  " 

95" 

100" 

—20° 
—15° 
—10° 

.1809 
.1864 
.1937 

.1916 
.1980 
.2067 

.2022 
.2097 
.2196 

.2128 
.2214 
.2325 

2235 
2330 
2454 

.2342 
2447 
2583 

2448 
2563 

2712 

.2554 
2679 
2842 

:i 

20 

—  5° 
0° 
5° 

.2001 

.2048 
.2083 

.2144 
.2206 
.2257 

.2287 
.2363 
.2430 

.2430 
.2521 
2604 

2573 
.2679 

.2778 

.271C 
.2836 
.2952 

2859 
.2994 
.3125 

.3002 
.3151 
.3299 

.3145 
.3309 
.3473 

3 

33 

10° 
15" 
20° 

.2096 
.2089 
.2054 

.2286 
.2298 

.2282 

2477 
.2506 
.2510 

.2667 
.2715 

.2738 

.2858 
.2924 
.2966 

.3048 
.3133 
.3195 

.3239 
.3342 
.3423 

.3429 
.3551 
.3651 

3620 
.3760 
3879 

39 
45 
5* 

25° 
30° 
35" 

.1992 
.1897 
.1768 

.2240 
.2169 
.2062 

.2489 
.2440 
.  2357 

.2738 
.2711 
.2651 

.2987 
.2982 
.2946 

.323fi 
.3253 
.3241 

.3485 
.3524 
.3535 

.3734 
.3795 
.3830 

3983 
.406(5 
.4124 

Economy  of  Compression  Machine. 

The  economy  depends  mainly  upon  the  back  pressure.  Maxi- 
mum economy  is  obtained  at  28  Ibs.  suction  pressure  and  about 
150  Ibs.  condensing  pressure.  Under  these  conditions,  for  a  non- 

CAPACITY  OF  COMPRESSOR  IN  TONS  OF  REFR.  UNDER  DIFFERENT 
BACK  PRESSURES. 


Diameter  [ 

Suction  or  Back  Pressure—  Gauge 

Com-     1  Dnmeter 

Stroke 

pressors 
Inches 

•Engine 
Inches 

Inches 

5 
Pounds 

10 
Pounds 

15.C7      j         20 
Pounds    1    Pounds 

25 
Pounds 

'  30 
Pounds 

7>^ 

H1A 

10 

6 

8    1       10          ii 

'3 

*5 

9 

\$y<z 

12 

13 

16 

,2O 

23 

26 

29 

1  1 

16 

15 

19 

24 

30 

34    |      39 

44 

12^*2 

18 

18 

26 

33 

40      ,        46     |         52 

59 

14 

20 

21 

39 

49 

60 

69           78 

88 

16 

.24 

24 

58 

73 

90     |      103 

118       132 

18 

26 

28 

81 

102 

125    i    143 

163    [   184 

20 

28^ 

32 

114 

142 

175     j      200 

229 

258 

22^ 

32 

36 

146 

I83 

225 

257 

294 

33  * 

25 

36 

42 

194 

244 

300 

343 

392 

442 

30 

44 

48 

324 

407 

500 

571 

654, 

736v 

COMPRESSOR. 


condensing  steam  engine,  consuming  coal  at  the  rate  of  3  Ibs. 
per  hour  per  I.  H.  P.  of  steam  cylinders,  24  Ibs.  of  ice-refriger- 
ating effect  are  obtained  per  Ib.  of  coal  consumed.  For  the  same 
condensing  pressure,  and  with  7  Ibs.  suction  pressure,  which 
affords  temperatures  of  0  degrees  F.,  the  possible  economy  falls 
to  about  14  Ibs.  of  "refrigerating  effect"  per  Ib.  of  coal  consumed. 

The  above  table,  compiled  by  the  York  Mfg.  Co.,  gives  the 
sizes  of  compressors  and  their  capacity  under  different  back  pres- 
sures, based  on  60°  condensing  water.  The  condensing  pressiire 
is  determined  by  the  amount  of  condensing  water  supplied  to 
liquefy  the  ammonia  in  the  condenser.  If  the  latter  is  about  1 
gallon  per  minute  per  ton  of  refrigerating  effect  per  24  hours, 
a  condensing  pressure  of  150  results,  if  the  initial  temperature 
of  the  water  is  about  56  degrees  F.  Twenty-five  per  cent,  less 
water  causes  the  condensing  pressure  to  increase  to  190  Ibs. 

The  work  of  compression  is  thereby  increased  about  20  per 
cent.,  and  the  resulting  "economy"  is  reduced  to  about  181  Ibs. 
of  "ice  effect"  per  Ib.  of  coal  at  28  Ibs.  suction  pressure,  and 
11.5  at  71  Ibs.  If,  on  the  other  hand,  the  supply  of  water  is 
made  3  gallons  per  minute,  the  condensing  pressure  may  be  con- 
fined to  about  105  Ibs.  The  work  of  compression  is  thereby  re- 
duced about  25  per  cent.,  and  a  proportional  increase  of  economy 
results. 

If  the  engine  may  use  a  condenser  to  secure  a  vacuum  an 
increase  of  economy  of  25  per  cent,  is  available  over  the  above 
figures,  making  the  Ibs.  of  "ice  effect"  per  Ib.  of  coal  for  150 
ibs.  condensing  pressure  and  28  Ibs.  suction  pressure  30.0,  and 
for  71  Ibs.  suction  pressure,  17.5.  In  this  case  it  may  be  assumed 
that  water  will  also  be  available  for  condensing  the  ammonia  to 
obtain  as  low  a  condensing  pressure  as  about  100  Ibs.,  and  the 
economy  of  the  refrigerating  machine  becomes  for  28  Ibs.  back 
pressure,  43.0  Ibs.  of  "ice  effect"  per  Ib.  of  coal,  or  for  71  Ibs. 
back  pressure,  27.5  Ibs.  of  ice  effect  per  Ib.  of  coal.  If  a 
compound  condensing  engine  can  be  used  with  a  steam  con- 

DIAGRAM  SHOWING   ECONOMY   AT  DIFFERENT  BACK   PRESSURES. 
25 


20 


10 


20 


15 


10 


40*     35°     30°     25°      20*     15°       10*       5°        0°      -5°    -10*  -15* 

£8      SI        45      39        33       2#       24-       19        16        13        9          6 

REFRIGERATOR   PRESSURE  4  TEMPERATURE. 


COMPRESSOR.  37 

sumption  per  hour  per  horse-power  of  161  Ibs.  of  water,  the 
economy  of  the  refrigerating  machine  may  be  25  per  cent,  higher 
than  the  figures  last  named,  making  for  28  Ibs.  back  pressure  a 
refrigerating  effect  of  54.0  Ibs.  per  Ib.  of  coal,  and  for  7  Ibs.  back 
pressure  a  refrigerating  effect  of  34.0  Ibs.  per  Ib.  of  coal.  (Prof. 
J.  A.  Denton.) 

In  the  above  diagram  the  line  marked  capacity  of  machine 
shows  tho  diminished  capacity  as  the  back  pressure  is  reduced. 
If  the  machine  has  a  capacity  of  10  tons  at  a  return  pressure 
of  28  pounds,  as  shown  by  vertical  height  of  the  curve,  it  has  a 
capacity  of  5  tons  only  with  a  return  pressure  of  _  6  pounds. 
Under  the  same  circumstances  the  cost  of  fuel  per  ton  is  in- 
creased in  the  ratio  of  the  vertical  heights  to  the  curve  marked 
cost  of  fuel,  namely,  from  14.5  to  25.  In  other  words  the  cost 
per  ton  is  nearly  doubled  while  the  capacity  is  halved.  The 
work  as  seen  by  the  curve  marked  work  required  diminishes  very 
slowly.  (De  La  Vergne  Co.) 

Dry  vs.  Wet  Compression. 

A  dry  compression  plant  will  need,  with  an  expansion  evaporat- 
ing system:  A  medium  size  compressor;  a  large  size  evaporating 
system;  a  small  amount  of  ammonia. 

A  dry  compression  plant  will  need,  with  a  flooded  evaporating 
system:  A  small  size  compressor;  a  small  size  evaporating  sys- 
tem; a  large  amount  of  ammonia. 

A  wet  compression  plant  will  need,  with  a  wet  compression 
evaporating  system:  A  large  size  compressor;  a  medium  size  evap- 
orating system;  a  medium  amount  of  ammonia. 

According  to  C.  Vollmann,  the  wet  compression  system  has  the 
following  advantages  over  the  dry  compression  system: 

First.  By  letting  the  ammonia  vapors  return  to  the  com- 
pressor in  a  partially  wet  state,  we  are  enabled  to  work  with  a 
higher  back  pressure,  thereby  having  the  ammonia  gas  in  the 
refrigerator  pipes  of  a  higher  density  than  if  the  vapors  were 
perfectly  dry.  Furthermore,  we  are  enabled  to  keep  the  refrigera- 
tor pipes  partially  filled  with  liquid  ammonia,  in  consequence  of 
which  the  surface  of  the  refrigerator  can  be  materially  reduced. 

Second.  By  keeping  the  compressor  parts  at  a  cool  tempera- 
ture, the  compressor  draws  in  a  greater  amount  of  vapors  than 
where  the  parts  are  highly  overheated.  With  a  dry  compressor, 
although  the  cylinder  is  water  jacketed,  the  internal  parts  are 
kept  at  a  yery  high  temperature,  and  when  the  dry  ammonia 
vapors  are  drawn  into  the  compressor,  they  immediately  get  heated 
up,  and  by  expanding  prevent  the  compressor  from  drawing  in  its 
full  amount  of  vapors. 

Third.  By  keeping  the  compressor  at  a  cool  temperature,  the 
compressor  oil  which  is  taken  into  the  compressor  through  the 
stuffing  box  cannot  evaporate,  but  is  kept  in  its  liquid  state,  and 
as  such  deposited  in  the  oil  collector. 

Fourth.  With  the  wet  compression  system,  the  engineer  in 
charge  knows  if  sufficient  ammonia  is  circulated  through  the  sys- 
tem or  not,  by  placing  his  hand  on  the  delivery  pipe.  If  this 
keeps  fairly  warm,  a  sufficient  amount  of  ammonia  is  passed 
through  the  system. 

In  regard  to  Vollmann's  theory  (No.  2)  that  a  larger  volume  of 
vapor  could  be  handled  by  the  wet  compressor  at  each  stroke, 
we  must  not  overlook  the  fact  that  the  interchange  of  heat  be- 
tween the  ammonia  and  the  walls  of  the  compressor  cylinder  is 
evidently  much  greater  than  anticipated  by  many,  as  was  proved 
in  the  tests  made,  at  the  test  plant  of  the  York  Mfg.  Co.  Six- 
teen of  these  tests  were  made  in  four  series  of  four  runs  each, 
the  speeds  used  being  40,  60,  80  and  100  revolutions  per  minute 


COMPRESSOR. 


in  each  series.  The  results  proved  that  while  the  liquid  handled 
is  slightly  less  with  dry  compression,  the  cooPng  done  was  about 
fifteen  per  cent,  more  with  dry  than  with  wet  compression,  and 
further  that  the  cooling  decreases  rapidly  toward  the  lower 
speeds  with  wet  compression. 

Tests  made  with  the  horizontal  double-acting  compressor  indi- 
cated that  the  results  were  even  more  in  favor  of  the  dry  com- 
pression than  those  obtained  previously  with  the  vertical  com- 
pressor. All  the  tests  were  made  at  the  standard  head  pressure 
of  185  pounds,  gauge,  and  it  was  observed  that  in  comparing  the 
tonnage  made  at  a  given  back  pressure  for  the  two  conditions 
that  the  difference  increases  rapidly  as  the  suction  pressure  de- 
creases. The  tonnage  made  with  five  pounds  suction  pressure  was 
nearly  three  times  that  made  with  wet  compression  at  the  same 
suction  pressure,  while  at  twenty-five  pounds  the  difference  was 
only  about  one-half  more  in  favor  of  dry  compression. 

In  a  series  of  tests  made  in  1904,  the  results  showed  that  the 
higher  the  temperature  of  the  discharge  gas,  the  more  cooling 
was  done  per  unit  of  piston  displacement  and  per  unit  of 
power  expended. 

In  tables  I  and  II  a  comparison  is  made  between  three  machines. 
The  vertical  single-acting  machine  of  100  tons  refrigerating  capacity 
is  taken  as  the  basis. 

The  wet  compression  machines  are  assumed  to  have  70% 
rolumetric  efficiency  when  operating  under  dry  compression  con- 
ditions. 

TABLE  NO.  I. 

Comparative  Amount  of  Work  that  can  be  gotten  out  of  18-inch  by  28-inch 
Compressors,  under  the  conditions  stated,  and  the  Size  and  Horse  Power  of*the  ' 
Engine  needed  to  drive  each  machine. 


Condition 

Type 
Machine 

COMPRESSOR 

ENGINE 

No. 

Size 

Volir 
metric 
Effi- 
ciency 

Tons 
Refrigr 

Size 

I.  H.  !». 

H.  P. 

Ton 

Bry  Comp. 
ry  Comp. 
Wet  Comp. 

Vertical  S.  A. 
Horiz.  D.  A. 
Horiz.  D.  A. 

2 

1 
1 

18x28 
18x28 
18x28 

80* 
70* 

100 
88 
64 

'26x28 

26  x28 
251x28 

170 
171.6 
167 

1  7 
1  95 
261 

TABLE  NO.  II. 

Comparative  Size  of  Compressor  required  to  do  100  tons  refrigration  under  the 
conditions  stated,  also  the  Size  and  Horse  Power  of  Engine  needed  to  drive  each 
machine. 


COMPRESSOR 

•ENGINE^ 

Condition 

Type 
Machine 

No. 

Size 

Volu- 
metric 
•Effi- 

|| 

Size 

I.  H.  P. 

H.P. 

per 

ciency 

Hc* 

Ton 

Dry  Comp. 
Dry  Comp. 
Wet  Comp. 

Vertical  S.  A. 
Horiz    D.  A. 
Horiz.  D.  A. 

2 
1 

1 

18  x28 
19ix28 
224x28 

80* 
70  < 

100 
100 
100 

26  x28 
28x28 
32ix28 

170 
195 
261 

1.7 
1.95 
2.61 

Conditions:— 15.67  Ibs.  suction  pressure;  185 Ibs.  discharge  pressure:  no  liquid 
cooling:  one-quarter  cut-off  in  steam  cylinder;  90  Ibs.  steam  pressure:  and  59 
revolutions  per  minute. 


The  Condenser 


A  large  condenser  surface  will  greatly  assist  the  economical 
working  of  the  machine.  The  amount  of  pipe  depends  on  the 
temperature  of  the  cooling  water,  as  with  warmer  water  a  higher 
latent  heat  of  the  medium  has  to  be  transferred  to  the  cooling 
water. 

Condenser  Surface. 

The  condenser  surface  equals  the  product  of  the  latent  heat  and 
the  amount  of  liquid  passing  the  compressor  per  minute,  divided 
by  the  heat  transmission. 

Example  continued :  How  large  is  the  surface  of  an  atmospheric 
condenser  for  an  18-ton  refrigerating  machine? 

hk 


F  = 


m  (t  —  ti) 

Where  h  •=  latent  heat  of  ammonia  at  85°  =  500;  k  =  amount 
of  ammonia  passing  the  compressor  p.  min.  (which  is  the  product 
of  the  cubic  capacity  of  the  compressor  and  the  weight  of  1  cb. 
ft.  of  gas  at  the  refr.  temp.  =  69.3  X  0.11  =  7.6);  m  =  number 
of  heat  units  transferred  per  minute  per  sq.  ft.  of  iron  pipe  per 
degree  of  difference  (m  =  1  for  atm.  condensers,  0.8  for  sub- 
merged condensers)  ;  t  =  temp,  of  ammonia  in  coils  =  85°  P.  ;  tt  = 
temp,  of  water  (mean  between  initial  of  70°  and  final  of  80°  — 


75° 


500  X  7.6 


F  = 


=  380  sq.  ft. 


1  (85  —  75) 

=  21  sq.  ft.  per  ton  of  refrigeration. 

For  safe  calculations  employ  for  atm.   condensers  the  following 
values  : 
Initial  temp,   of  water  .....  50°     55°     60°     65°     70°     75°     80°     85' 

Condensing  surface  in  sq.  ft. 
per   ton    of    refr  ..........   19      20.5  22      24      26      28       30.534.5 

In  case  of  submerged  condensers  we  have  to  add  20  per  cent,  to 
the    above    amount    of    surface,    as    the    heat    transmission    is   0.8 
instead  of  1. 
Amount  of  Cooling  Water. 

By  calculating  the  amount  of  cooling  for  above  condenser  we 
have  to  divide  the  latent  heat  of  the  liquid  passing  the  com- 
pressor per  minute  (which  is  7.6  Ibs.)  by  the  amount  of  heat  which 
has  been  taken  up  by  the  cooling  water  (difference  between  the 
final  and  initial  temperature  of  the  water). 

500  X  7.6 
A  =  --  =  380  Ibs.  per  minute. 

80  —  70 

=  2.6  gal.  per  minute  per  ton  of  refr. 

For  safe  calculations  use  the  values  given  in  the  following 
table,  based  on  a  final  temperature  of  water  of  95°  F.  : 

COOLING   WATER    TEB   TON    OF   REFRIGERATION. 
Initial  temperature  of  water  50°      %   gal.  per  minute. 
55°       % 
60°       % 
65°    1 
70°    1H 
75°    1% 
80°    2 
85°    2% 

For  submerged  condensers  allow  at  least  20  per  cent,  more 
water. 


CONDENSER. 
d 


FIG.    13— VARIOUS    TYPES    OF    AMMONIA    CONDENSERS. 

a,  Standard  top  fed.  c,  top  fed,  continuous  wound  coil,  c,  bottom 
fed  ("De  La  Vergne").  d,  "American  Linde."  e,  "Prick."  f  and  g, 
double  pipe,  h,  submerged  condenser,  i,  shell  and  coil  condenser. 


CONDENSER. 


Where  local  conditions  are  favorable  to  allow  the  condenser 
to  be  put  on  the  roof  and  exposed  to  the  winds,  the  same  cooling 
water  may  be  used  over  and  over  again,  provided  the  atmospheric 
condenser  is  built  sufficiently  high,  as  it  is  done  in  Germany. 

Another  method  to  economize  is  by  employing  a  cooling  tower. 
(See  notes  on  cooling  towers.) 

Builders  of  refrigerating  machines  rate  the  atmospheric  am- 
monia condensers  for  average  conditions  as  follows: 

The  Fred  W.  Wolf  do. :  22.5  sq.  ft.  per  ton  of  refrigeration ; 
condensers  are  24—2"  pipes  high  by  20  fet.  long. 

The  De  La  Vergne  Machine  Co. :  13  sq.  ft.  per  ton  of  refrigera- 
tion ;  condensers  are  18 — 2"  pipes  high  by  20  ft.  long: 

The  Linde  Co.  of  Germany :  Submerged  condensers  have  3'2  sq.  ft. 
for  small  machines  of  10  to  25  tons  down  to  19.5  sq.  ft.  for 
machines  of  100-ton  refr.  capacity ;  atmospheric  condensers  are 
48 — 1%"  pipes  high  (2"  centers)  by  16' — 7"  long. 

Double  pipe  condensers  have  of  late  come  more  to  the  foreground. 
Their  high  efficiency  is  due  to  the  perfect  heat  exchange,  which 
is  obtained  through  observing  the  counter-current  principle.  They 
are  rated  on  a  basis  of  about  14%  foot  of  pipe  per  ton  of  re- 
frigeration. 

Most  commonly  we  find  2-in.  pipe  inside  of  3-in.  pipe  or  1*4 -in. 
pipe  inside  of  2-in.  pipe.  Some  manufacturers  prefer  to  circulate 
the  cooling  water  through  the  inner  pipe,  some  through  the  outer 

Tables  No.  Ill  and  No.  IV  give  the  capacities  and  horse  power  per  ton  refrig- 
eration of  one  section  counter-current  double-pipe  condenser,  li-inch  and  2-inch 
pipe.  12  pipes  high.  19  feet  outside  water  bends,  for  water  velocities  100  feet  to 
400  feet  per  minute;  initial  temperature  of  condensing  water  70  degrees. 

TABLE  NO.  Ill  -High  Pressure  Constant. 


CONDENSING  WATER 

t\ 

J3 

o 
c 

HORSE  POWER  PER  TON 
REFRIGERATION 

111 

i 

re  o> 
Utf 

Condensing 
Pressure. 
Lbs.  per  square 

Velocity 
through  ll-inch 
pipe. 
Feet  per  min. 

Total  Gallons 
used  per  min. 

Gallons  per 
min,  per  ton 
refrigeration 

"Sufi 

§W£.S 

••g-S«£ 

'C  3-°  rt 

fes^§ 

£          00 

Engine 
driving 
compressor 

Circulating 
water  through 
condenser 

Total  engine 
and  water 
Circulation 

100 

7.77 

.16 

2.28 

,6.7 

185 

1.71 

0.0016 

7116 

150 

.  11.65 

.165 

5.75 

10. 

185 

1.71 

0.004 

.714 

200 

15.54 

.165 

•9.98 

13.4 

185 

1.71 

0.007 

.717 

250 

19.42 

.18 

15. 

16.4 

185 

1.71 

0.011 

.721 

300 

23.31 

.24 

21.6 

18.8 

185 

1.71 

0.016 

.726 

400 

.31  .08 

1.30 

37.8 

24. 

185 

1.71 

0.030 

.74 

pipe.  The  double  pipe  condensers  are  built  18  ft.  long  and  from 
2  to  12  pipes  high.  For  large  machines  take  several  sections,  but 
not  over  12  pipes  high. 

Tests  made  at  York  determined  the  value  of  a  square  foot  of 
condensing  surface  under  different  conditions. 

The  data  relate  only  to  70°  condensing  water,  and  the  ralues 
given  will  not  be  true  for  any  other  temperature  or  condition  than 
those  stated. 

The  following  tables  show  the  effect  of  increasing  the  con- 
densing water  passing  through  a  double-pipe  condenser,  to  do  cer- 
tain work.  If  "capacity"  is  the  requirement,  table  No.  Ill  shows 
what  can  be  done  and  what  the  cost  in  power  will  be.  If  a 
"re-duction  in  horse-power"  is  the  requirement,  table  No.  IV 
shows  how  to  obtain  it  and  at  what  expense. 


TABLE  NO.  Ft— Capacity* Constant. 


100 

7.77 

0.777 

2.28 

10. 

225 

2i04 

0.001 

?.041 

150 

11.65 

1.165 

5.75 

10. 

185 

.71 

0.004 

.714 

200 

15.54 

1.554 

9.98 

.10. 

165 

.54 

0.009 

.549 

250 

19.42 

1.942 

15. 

10. 

155 

.46 

0.018, 

.478 

300 

23.31 

2.331 

21.6 

10. 

148 

.40 

0.030 

.43 

400 

31.08 

3.108 

37.8 

10. 

140 

.33 

0.071 

.401 

NOTES— Above  tables  are  based  on  the  heat  transmission  obtained  for  various, 
•velocities  of  water,  as  averaged  up  from  York  Manufacturing  Company's  tests  on 
double-pipe  condensers. 

The  horse  power  per  ton  is  for  single-acting  compressor  and  15.67  Ibs.  suction 
pressure. 

The  friction  in  water  pump  and  connections  should  be  added  to  water  horse 
power  and  to  total  horse  power. 


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NOTES  ON  COMPRESSION  MACHINES.      43 

CAPACITY  OF  SMALL  COMPRESSORS.  (VERTICAL  SINGLE  ACTING.) 


If 

j 

1 
"x 

=  2 

* 

°'U 

f 

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2'  5" 
3' 

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6  10 

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6 

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3'  6" 
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4'  4" 
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'  4 
'  4 
'  6 
'  6 

.  4'  S'  . 
4'  8" 
48' 

4'  S" 

'  3 
3 
3 
3 

NOTES  ON  COMPRESSION  MACHINES: 


PART   III— APPLICATION    OF    MECHANICAL 
REFRIGERATION 


Insulation 

The  insulation  of  cold  storage  rooms  is  a  matter  of  vital  im- 
portance when  viewed  from  an  economic  standpoint.  A  large 
percentage  of  the  actual  work  of  a  refrigerating  machine  is  re- 
quired to  make  up  for  transfer  of  heat  through  the  walls,  floor* 
and  ceilings  occasioned  by  improper  insulation. 

The  general  rule  applied  to  all  insulation  is:  An  air-tight  sur- 
face towards  the  source  of  heat  and  insulating  strata  towards 
the  cold  side  of  the  wall. 

Attention  may  be  called  to  the  following  points: 

(1)  Air  is  one  of  the  best  non-conductors  of  heat,   but  it  must 
be    kept    still;    if    it    is    allowed    room    to    form    currents    it    will 
convey  a  large  quantity  of  heat  from  the  outer  wall  to  the  inner 
wall   by    convection,    since   rapid    currents    are    formed    when    air 
is  free   to   move  between   walls   differing  only  a   few   degrees   in 
temperature. 

(2)  Filling  in  with  loose  non-conducting  material  must  be  done 
with  great  care,  since  it  is  liable  to  settle  in  places. 

(3  The  penetration  of  air  and  moisture  are  to  be  specially 
guarded  against  by  the  use  of  pitch  in  connection  with  brick  or 
stone,  or  paper  when  wood  is  used. 

(4)  Materials    should    be    selected    for    insulation    that    are    free 
from    unpleasant    odor    and    non-absorbent;    in    wood,    spruce    i* 
preferred,  since  it  is  free  from  knots,  has  little  or  no  odor,  and 
is,  at  the  same  time,  comparatively  cheap. 

(5)  In    applying   wooden    insulation    all    the   joints    between    the 
boards  should  be  laid  in  white  lead,  and  triangular  wooden  strips 
with  paper  behind   should  be  put  in   every   corner  in   the   room. 
The  paper  between  the  layers  of  boards  must  be  carefully  folded 
in  the  corners  so  as  not  to  break,  and  laid  so  that  the  edges  of 
the  paper  overlap  each  other. 

(6)  The    flow    of   heat   is    nearly    proportional    to    the    difference 
of   temperature   between   the   inside    and    the   outside    wall;    this 
circumstance   must  be  taken   into   consideration   in   arranging   in- 
sulation;  what  would  be  sufficient  in  a  cold  storage  room  to  be 
kept  at  36  degrees  would  be  totally   inadequate  in   a   case   of  a 
freezing  room  to  have  a  temperature  of  5  to  10  degrees.     It  is  a 
good  plan  to  locate  a  freezing  room  inside  of  a  cold  storage  room 
so    that    the    difference    of    temperature    between    its    inside    and 
outside  walls  may  be  more  moderate. 

(7)  The   best   insulation   is   none    too    good,    and    is   by   tar   tha 
cheapest  in  the  end. 

Fireproof  Cold  Storage  Warehouse  Construction. 

(J.  E.  Starr,  A.  S.  R.  B.     Trans.  1907.    Abridged.) 

Three  classes  of  fireproof  construction  : 

Class  A.  Cold  storage  buildings  erected  with  outer  and  inner 
walls  of  tile,  the  outer  wall  not  carrying  any  weight  but  its  own, 
and  the  floors  a  combination  of  concrete  and  tile,  weights  carried 
on  the  inner  walls  and1  partitions.  Insulation  between  inside  and 
outside  wall  a  continuous  fill. 

Class  B.  Cold  storage  warehouse  containing  an  inside  building, 
with  reinforced  concrete  columns  and  girders,  and  with  floors  of 
either  reinforced  concrete  or  combination  of  reinforced  concrete  and 
tile,  all  weights  carried  on  columns.  Outside  walls  either  of  brick 


INSULATION.  45 

or  tile,  or  a  combination  of  both.  Inside  walls  of  vitrified  tile.  In- 
sulation between  inside  and  outside  walls  a  continuous  fill. 

Class  C.  Cold  storage  building  with  iron  framework  with  weights 
carried  partially  on  columns  and1  partially  on  outside  brick  walls, 
all  ironwork  covered  with  fireproofing.  Inside  wall  of  vitrified  tile 
Insulation  between  inside  and  outside  walls  a  continuous  fill. 

Of  Class  A  (all  tile)  one  example  may  be  quoted  of  a  three-story 
house  in  Washington  Court  House,  Ohio. 

This  house  consisted  of  an  outside  wall  of  two  4-inch  hollow 
vitrified  tile,  an  inside  wall  of  one  course  of  4-inch  vitrified  tile 
standing  eight  inches  away  from  the  outside  wall.  The  floors  rested 
on  the  inside  wall  and  on  the  partitions  which  later  divided  the 
house  into  three  sections. 

The  space  between  inner  and  outer  walls  was  filled  with  granu- 
lated cork,  making  an  unbroken  fill  from  bottom  to  the  small  garret, 
or  a  circulating  air  space  between  the  top  floor  of  the  cold  rooms 
and  the  roof.  The  top  of  this  filled  space  was  closed  with  tile  which 
could  be  easily  taken  off,  so  that  if  any  settling  occurred  it  might 
be  observed  and  filled  in. 

Experience  of  four  years  has  shown,  however,  that  little,  if  any, 
settling  occurs.  Experience  in  filling  an  8-inch  space  showed  that 
the  cork  would  not  "bridge"  and  leave  voids  in  the  8-inch  space 
even  when  filled  from  a  height  of  twenty  or  thirty  feet. 

The  inside  wall  was  therefore  entirely  surrounded  by  insulation 
and  no  heat  could  pass  through  it  without  first  passing  through  the 
cork,  except  at  the  very  small  areas  where  the  inside  and  outside 
wall  were  tied  by  extending  the  partions  through  to  the  outside  wall. 

The  tile  was  laid  up  in  cement  mortar  and  panels  of  outside  wall 
surface  25  feet  wide  and  33  feet  high,  have  successfully  withstood 
wind  pressure  and  all  outside  influence. 

In  this  particular  building  the  floors  were  of  the  well  known 
Johnson  type.  This  consists  of  a  reinforced  concrete  tension  mem- 
ber, about  one  inch  thick,  covering  the  entire  span  or  "bay."  On 
top  of  these  two  courses  of  6-inch  tile  was  laid  a  finished  cement 
wearing  floor. 

It  will  be  observed  that  this  method  of  construction  places  the 
tile  in  compression  while  the  thin  concrete  with  its  strengthening 
rods  and  web  are  in  tension. 

Long  spans  can  thus  be  successfully  built  to  carry  far  in  excess 
of  the  maximum  cold  storage  load1  of  400  pounds  per  square  foot. 

Partitions  were  made  with  double  4-inch  tile  with  from  six  to 
eight  inches  of  cork  filled  space  between. 

The  first  building  of  Class  B  was  nine  stories  high  and  was  built 
in  St.  Paul,  Minn. 

The  building  proper  was  entirely  carried  on  columns  very  much 
as  our  present  skyscrapers  are  built,  excepting  that  the  columns 
were  all  of  reinforced  concrete,  and  the  outer  skin  was  not  car- 
ried on  the  outside  girders  as  in  the  case  of  office  buildings,  but 
was  entirely  independent  of  the  main  structure  and  standing  about 
eight  feet  away  from  it  at  all  points. 

The  outside  wall  was  only  12  inches  thick  from  bottom  to  top, 
but  was  reinforced  by  an  imbedded  "I"  beam  framework. 

There  was  only  about  a  square  inch  of  conducting  material  be- 
tween the  outside  wall  and  the  inside  structure  at  the  head  of  each 
column  and  its  conducting  effect  practically  nil  as  compared  to  the 
total. 

As  the  floors  and  outside  columns  and  girders  were  thus  about 
eight  inches  from  the  outside  wall  it  was  only  necessary  to  build 
from  floor  to  ceiling  a  4-inch  vitrified  tile  wall  and  fill  the  8-inch 
space  with  the  non-conducting  material  giving  the  same  continuous 
insulation  as  at  first  described  in  case  of  Class  A. 

The  outsid'e  wall  was  thoroughly  waterproofed  by  a  thick  odor- 


46  INSULATION. 

less  coating  on  the  inside  (which  may  be  in  time  followed  up  by 
an  outside  water  proofing). 

The  floors  in  this  building  were  6-inch  reinforced  concrete  or 
reinforced  concrete  girders  and  beams  in  spans. 

The  insulation  of  floors  was  made  on  top,  using  either  Lith  or 
cork  board  from  two  to  four  inches  thick,  depending  on  conditions. 

These  insulating  boards  were  laid  on  the  floor  slap,  well  "doped," 
with  odorless  pitch  and  waterproofed  on  top.  Over  this  a  two- 
inch  concrete  floor  was  laid,  reinforced*  with  a  wire  web  and  the 
whole  finished  off  with  a  %-inch  wearing  floor  of  cement  and  sand 
rendered  waterproof. 

Partitions  were  of  double  4-inch  hollow  tile  with  insulating  filled 
space  between  from  four  to  eight  inches. 

Under  the  Class  G  of  construction  comes  the  cold  storage  build*- 
ing  of  the  Murphy  Storage  &  Ice  Co.,  of  Detroit.  This  was  a  ten- 
story  building  constructed  with  built-up  steel  columns  and  with 
steel  girders  running  longitudinally  with  the  greatest  dimension  of 
the  building,  the  end  of  girders  resting  on  the  walls,  and  with  "I" 
beams  running  between  the  giroTers  and  from  the  girders  to  the 
walls  on  a  spacing  of  a  little  over  four  feet.  The  walls  therefore 
carried  their  share  of  the  weight  of  the  outside  spans.  The  floors 
were  of  a  combination  tile  and  concrete. 

Four-inch  tile  walls  were  built  from  floor  to  ceiling  flush  with 
the  edge  of  this  floor,  leaving,  therefore,  a  continuous  fill  from 
top  to  bottom  eight  inches  thfck,  excepting  where  the  "I"  beams 
ran  into  the  wall  at  each  story  on  centers  of  a  little  over  four 
feet. 

The  ends  of  the  "I"  beams  which  projected  through  the  8-inch 
space  between  the  edge  of  the  floor  and  the  outside  wall  were  care- 
fully wrapped  with  hair  felt  dipped  in  an  odorless  compound  and 
made  a  tight  joint  with  the  outside  wall. 

The  inner  surfaces  of  the  outside  wall  were  coated  continuously 
from  top  to  bottom  with  a  thick  coat  of  odorless  waterproofing 
material  and  the  inside  4-inch  wall  was  built  up  in  the  same  man- 
ner as  described  for  Classes  A  and  B  and  the  space  between  filled 
with  granulated  cork. 

The  columns  and  "I"  beams,  wherever  exposed,  were  covered 
with  a  hollow  tile  fireproofing,  plastered  on  the  outside.  The 
partitions  were  constructed  of  double  walls  of  hollow  tile  with  a 
fill  of  from  four  to  eight  inches  of  insulating  material  between,  as 
in  the  case  of  the  other  houses  described.  The  floors  were  also 
Insulated,  as  before  described,  by  laying  from  two  to  four  inches 
of  lith  board  on  the  floors,  thoroughly  "doped"'  and  waterproofed 
with  a  2-inch  course  of  concrete  on  top,  reinforced  with  wire  netting 
and  a  finishing  course  of  %-inch  of  well  troweled  cement  and  sand. 

The  floors  on  all  three  classes  of  these  buildings  were  finally 
waterproofed  by  a  concrete  filler  and  a  concrete  paint  presenting 
a  glassy  surface,  and  impervious  to  water. 

All  of  the  storage  rooms  in  these  buildings  were  singularly  free 
from  odor,  and  the  air  was  unusually  keen  and  sweet  as  com- 
pared with  buildings  constructed  with  wooden  insulation,  as  all  of 
the  surfaces  were  either  of  vitrified  tile  or  waterproofed  concrete, 
neither  of  which  absorb  or  give  out  odors.  It  may  also  be  pointed 
out  that  the  continual  passing  of  the  air  over  the  calcium  brine 
surfacers  greatly  purified  the  air,  as  it  has  been  proven  that 
chloride  of  calcium  is  quite  effective  as  a  germicide.  The  re- 
searches on  this  subject  conducted*  by  Dr.  O.  Profe,  Dr.  Hesse  and 
other  German  authorities  show  conclusive  results  on  this  point. 

All  doors  throughout  all  of  these  buildings  were  covered  with 
either  galvanized  iron  or  tin  in  accordance  with  the  underwriters' 
specifications. 

It  was  ascertained  that  where  buildings  were  divided  into  sepa- 


INSULATION. 


47 


rate  fire  risks,  the  conduction  from  one  floor  risk  to  the  other 
through  the  continuous  girders  could  be  best  avoided  by  placing 
the  skeleton  framework  of  each  fire  risk  entirely  on  its  own  col- 
umn, instead  of  using  a  common  column  between,  the  two  fire 
risks.  This  allows  a  continuous  fill  of  insulating  material  between 
each  fire  risk. 

It  has  been  proven  conclusively  that  almost  any  of  the  insulating 
materials  in  common  use  when  put  up  between,  fireproof  walls  of 
tile  or  brick  do  not  contain  sufficient  air  to  support  combustion  in 
case  of  fire  playing  on  the  inner  or  outer  wall.  Tests  have  been 
made  by  making  an  opening  of  good!  size  in  outer  wall,  exposing 
the  insulation,  and  building  a  hot  bonfire  on  the  outside  imme- 
diately against  the  opening,  and*  continuing  the  test  for  several 
hours.  At  the  end  of  the  test  it  was  found  that  the  insulation  was 
only  charred  a  few  inches  hack  from  the  opening. 

In  a  general  way  it  may  be  stated  that'the  cost  of  the  buildings 
per  cubic  foot,  fully  insulated,  will  run,  if  anything,  less  than  the 
cost  of  a  wooden  building  whether  of  the  ordinary  girder  or  floor 
beam  type,  or  of  mill  construction,  or  of  a  combination  of  iron, 
and  wood,  and  that  the  general  method  here  described  of  prac- 
tically constructing  the  inside  of  a  building  with  a  continuous 
course  of  insulation  all  around  has  entirely  obviated  many  of  the 
difficulties  which  might  be  apprehended  in  the  use  of  these  ma- 
terials. 

The  fire  risk  is  also  a  very  important  feature  as  the  first  asking 
rate  on  these  buildings  was  only  40c.  on  contents,  which  is  only 
about  1-3  the  average  rate  on  wooden  or  mill  constructed  buildings, 
and  in  some  cases  %  the  rate.  As  to  the  buildings  themselves,  the 
owners  as  a  rule  feel  that  they  are  practically  indestructible  and 
carry  their  own  insurance. 

A  comparison  of  the  fire  risk  in  a  fireproof  cold  storage  ware- 
house with  the  average  so-called  fireproof  building  is  not  a  fair  one 
on  account  of  the  fact  that  there  are  practically  no  openings  into 
the  main  part  of  the  warehouse,  while  the  average  fireproof  office 
building  is  vulnerable  in  a  general  conflagration,  owing  to  the  fact 
that  a  very  large  percentage  of  its  outside  surface  is  made  up  of 
window  openings,  and  that  it  is  divided  into  small  rooms  containing 
in  the  doors,  trim  and  other  woodwork  a  large  amount  of  in- 
flammable material. 

TANK  INSULATION. 


LONGITUDINAL  SECTION. 


TRANSVERSE  SECTION, 


FIG.   14. 


48  INSULATION. 

TRANSMISSION    OF   HEAT   THROUGH    1%"    TO    2"   IRON    PIPES    PER 
SQ.   FT.    PER   HOUR   PER   DEGREE   OF    DIFF.    IN   TEMP. 
Mode  of  Operation  B.  T.  U.  Example. 

Ammonia  gas  inside,  water  out- 
side           50     Submerged   Condenser. 

Ammonia     gas     inside,     running 

water    outside 60     Atmospheric  Condenser. 

Ammonia  gas  inside,   brine   out- 
side          25      Brine    Tank. 

Ammonia   gas   inside,   wort   out- 
side   (counter    current) .......      60     Dir.    exp.    beer  cooler. 

Ammonia    gas    inside,    air    out- 
side          2-8      Direct  expansion. 

Cold    >brine    inside,    water    out- 
side          80      Water    Cooler. 

Cold    brine    inside,    water    out- 
side           60     Distilled  Water   Cooler. 

Cold   brine   inside,    wort  outside     70     Brine  Beer  Cooler. 

Cold1  brine   inside,   wort   outside 

(counter    current)     75    Baudelot  Cooler  with  brine. 

Am.  liquor  inside,  water  outside 

(counter    current)     60     Absorber. 

Am.    liquor    inside    and    outside 

(counter  current)    50     Exchanger. 

Water  inside  and  outside  (count- 
er   current)     50      Exchanger. 

Steam      inside,      water      outside 

(counter    current)     500     Steam    Condenser. 

Steam     inside,     water     or     am. 

liquor    outside    300     Am.  Liquor  Still. 

Steam  insid'e,   air  outside 2-3     Steam  pipes. 

TRANSMISSION    OF    HEAT    THROUGH    VARIOUS    INSULATIONS    PER 
SQ.   FT.  IN  24  HOURS  PER  DEGREE  OF  DIFF.  IN  TEMP.       B.T.U. 

2  boards    with   paper,    1   inch   air   space,    5   inches    Nonpareil 
sheet   cork,   paper,    board 0.9 

1  board    with    paper    3    inches    Nonpareil    sheet    cork,    paper, 
board     2.1 

1  board  with  paper,  2  inches  Nonpareil  sheet  cork,  2  boards 

with   paper 3 

2  boards    with    paper,    4    inches    granulated    cork,    2    boards 

with  paper    1.7 

1  board,  2%   inches  mineral  wool,  paper,  board 3.62 

1  board,  paper,  1  inch  mineral  wool,  paper,  board 4.6 

2  boards  with  paper,  8  inches  mill  shavings,   paper,  2  boards 

with   paper,    dry 1.35 

Same,   damp    2.1 

1  board,   2  inches  air  space,   board,   2   inches    "Lath,"    paper, 
board     1.8 

4  boards,  1  inch  flax  sheet  lining,  2  papers 2.3 

1  board,    6    inches    silicated    strawboard    (air    cell),    layer    of 

cement     2.5 

4  boards,  4  quilts  of  hair 2.52 

2  double  boards  with  2  papers,  1  inch  hair  felt 3.32 

1  board,  paper,  2  inches  calcined  pumice,  paper,  board 3.4 

1  board,  2  inches  pitch,   board 4.25 

4  double  boards   with  paper   (8  boards)   and   three    %    inches 

air    spaces    2.7 

2  double  boards  with  paper  (4  boards)  and  1  inch  air  space..  3.71 

4  boards  with  2  papers,  solid,  no  air  space 4.28 

Brickwall,    3    inches,    hollow    tile,    4    inches    mineral    wool,    3 

inches  hollow  tile,   cement  plaster 0.7 

Concrete  floor,  3  inches  book  tiles,  6  inches  dry  underpiling, 
double  space  hollow  tile  arches,  cement  plaster 0.8 


INSULATION. 


49 


TABLE  OF  RELATIVE  VALUE  OF  NON-CONDUCTING  MATERIALS. 


Geese  Feathers  1.08 
Felt,  Hair   or  Wool      .    .    .  t. 
Carded  Cotton     i. 

Charcoal  from  Cork  .,    .    4   -8? 

Sawdust  68 
Paste    of   Fossil   Meal   and 
Ha.r     63 
Wood  Ashes    61 

Asbestos,  ribrous  .  .  .  .  ,  .  .36 
Plaster  of  Paris,  dry  ...  .34 
Clay,  with  vegetable  fibre  .  .34 
Anthracite  Coal,  powdered  .  .29 

Fossil  Meal     79 
Straw  Rope,  wound  spirally     77 
Rice  Chaff,  loose     ....     76 
Carbonate  Magnesia    .    .    .    .76 
Charcoal  from  Wood  .    .    .,    75 

Loam,  dry  and  open  .     .     .  .5; 
Chalk,  ground  .Spanish  white  ." 
Coal  Ashes  ^ 
Gas-house  Carbon  .    .    .    Y',47 

Air  Spare,  undivided  .'  .  .  .at 
Sand  /  ..17 
Baked  Clay,  Brick  .  .  ..  ,.07 
Glass  •.  ,  .  ..05 

CEILING  &  FLOOR  INSULATION 


\\V—  2''X  4" STUDDING 
-V'BOARD 
-  2''CORKBOARD 
-CEMENT  FINISH 


1  CEMENT 
2"CONCRETE 

2  'CORKBOARD 
CONCRETE 
HOLLOW  TILE 
CEMENT  FINISH 


WALL  INSULATION 


2  LAYERS  OF  PAPER 

3  "CORKBOARD 
CEMENT  FINISH 


-CEMENT 
-  3"CORKBOARD 
> — CEMENT  FINISH 


\V—  2  LAYERS  OF  PAPER 

V— 2'/5  CORKBOARD 

-CEMENT  FINISH 


CEMENT 
2ya"  CORKBOARD 
NT  FINISH 


\\Y — CEMENT 

A\\ —  2"CORKBOARD 

)— 2  LAYERS  OF  PAPER 
-  2  CORKBOARD 
-CEMENT  FINISH 


CEMENT 
2"CORKBOARD 
CEMENT  FINISH 


308  A 


CEMENT 

1V2"  CORKBOARD 

2  LAYERS  OF  PAPER 

1W  CORKBOARD 

CEMENT  FINISH 


FIG.    15— DETAILS   OF    INSULATION. 


INSULATION. 


1  BOARDS 

2  LAYERS  OF  PAPER 
3"CORKBOARD 
CEMENT  FINISH 


T.    A  G.    BOARDS 
1    LAYER  OF  PAPER 
3  'CORKBOARD 
1    LAYER  OF  PAPER 
T.    &  G.    BOARDS 


1  X  3    STUDDING 

CROSSHATCHED 

I    LAYER  OF  PAPER 

S"CORKBOARD 

1    LAYER  OF  PAPER 

T.    A  G.    BOARDS 


1  X  3    STUDDING  CROSSHATCHED 

3''CORKBOARD 

CEMENT  FINISH 


PORTLAND  CEMENT 

3"CONCRETE 
3"CORKBOARD 
1  LAYER  OF  PAPER 
//^"BOARDS 


PORTLAND  CEMENT 

3"CONCRETE 

3"CORKBOARD 

1   LAYtR  OF  PAPER 

T.   &  G.   BOARDS 


PARTITION  INSULATION 


CEMENT  FINISH 

2'CORKBOARD 

1"BOARD 

2"X  4"STU0DING 

1    LAYER  OF  PAPCR 

2"CORKBOARD 

CEMENT  FINISH 


\\Y—  CEMENT  FINISH 


\\ V —  \yi  CORKBOARD 


PITCH  CEMENT 

2'CORKBOARD 

2  LAYERS  OF  PAPER 

1  V2 CORKBOARD 

CEMENT  FINISH 


T.    A  G.    BOARDS 
1    LAYER  OF  PAPER 

1  1/2  CORKBOARD 

1    LAYER  OF  PAPER 

2  CORKBOARD 
T.    &  G.    BOARDS 


s —  CEMENT  FINISH 

V'CORKBOARD 

1  ''BOARD 

2  X  4  STUDDING 

1  LAYER  OF  PAPER 
TCORKBOARD 
CEMENT  FINISH 


309  A 


FIG.    16— DETAILS   OP   INSULATION. 


-16 


X 


DETAIL   OF   SQUARE   SHELVING 
NOTE:  VERTICAL   PIECES  TO  BE 
NAILED  UP  WELL  THEN  DIP  ENDS 
OF  HORIZONTAL  PIECES  IN  PITCH 
AND  TAR  MIXED  AND  DRIVE  IN  TIGHT 


FOR  GROUND  FLOORS. 

T.A. G.BOARDS  1  THICKNESS 
V'X    2"SQUARE  SHELVING 


FOR  INTERMEDIATE  FLOORS. 

T.A  G.  BOARDS   1   THICKNESS  ' 

1"X  2"SQUARE  SHELVING 
HEAVY  COAT  OF  PITCH 

4*  DRY  FILLING 

COMMON    BOARDS  1  THICKNESS 
AVY  COAT  OF  ODORLESS  P.ITCR 
X  2"  SQUARE    SHELVING 
T.A  G.BOARDS  2  THICKNESSES 
LAYER  INSULATING  PAPER  2  PLY 


FOR  PARTITION  WALLS. 

^-T. A  G.BOARDS   1   THICKNESS 

•~1   LAYER  INSULATING  PAPER  2  PLY 

-1"X    2"SQUARE  SHELVING 

HEAVY  COAT  OF  ODORLESS  PITCH 

COMMON    BOARDS  1   THICKNESS 

4-"  DRY  FILLING 


PLAN  OF  BRICK  WALL  AND 
PARTITION  INSULATION. 


FIG.    17— DETAILS   OF   INSULATION. 


ICE  HOUSE  FLOORS 

INCLINE  TOWARD    CENTER  S" 


GROUND 


FOR  WALLS  OF  FRAME  BUILDING 


SECTION  THROUGH  DOOR 


2  PLY 

V'X   2"SQUARE  SHELVING 

=-  HEAVY  COAT  OF  ODORLESS  PITCH 
;=—  COMMON  BOARDS  1    THICKNESS 
—  6"TO    8  "OF  DRY   FILLING 


INSULATION  OF  END  JOISTS. 


SECTION  THROUGH  WINDOW 


TEMP.35°TO  30C 


INSULATION  OF  BRICK  WALLS. 

TEMP.30°TO  25° 


FOR  FREEZING  ROOMS 


;  • 

=-  HEAVY  COAT  OF 

ii^ 

^  HEAVY  COAT  OF 

ODORLESS  PITCH 

.-^   •• 

ODORLESS  PITCH 

:="•  COMMON  BOARDS 

1"X  2"  SQUARE 

'••4- 

1   THICKNESS 

SHELVING 

S"OF  DRY  FILLING           J%/<, 

COMMON  BOARDS 

SHELVING. 

•••'^r 

8"OF  DRY  FILLIN 

*  T.A  G.  BOARDS 

-  '- 

1   THICKNESS 

COMMON.  BOARDS 
1   THICKNESS 

*  T.4  G.BOARDS 

; 

1   THICKNESS 

;-'"•;-. 

f; 

: 

;•-'-: 

j 

YM 

•-'-• 

•    , 

\ 

1 

-HEAVY  COAT  OF 
ODORLESS  PITCH 

•  COMMON  BOARDS 
2  THICKNESSES 

-T.4  G.BOARDS 
2  THICKNESSES 

1  LAYER  OF    IN- 
SULATING PAPER 

2  PLY 

"OF  DRY   FILL 

'X2"SOUARE 


SECTION  THROUGH 
PARTITION 
DOOR. 


FIG.    IS— DETAILS   OF   INSULATION. 


INSULATION.  53 

NOTES   ON   INSULATION: 


General  Cold  Storage 


Cold  storage  comprises  the  preservation  of  perishable  articles 
by  means  of  low  temperature.  Refrigeration  is  produced  by 
direct  or  indirect  expansion  or  forced  air  circulation. 

COLD    STORAGE    TEMPERATURES. 


ARTICLES 

c  Fahr 

FRUIT 

FISH                   J 

VEGETABLES 

Apples  ,. 
Bananas  »  

34-36 

Fresh   Fish  „.... 
After  Freezing  

25-30 
18-20 

Asparagus  .-  
Cabbage  

.33-35 

7  0    -    1  A 

Berries,  fresh  „  
Cranberries  
Cantaloupes  
Dates,  Figs,  etc  
Fruits,  dried  „  
Grapes  

36-40 
33-34 
33-40 

35-40 
34  -  36 

Dried  Fish  
Oysters  in  shell  
Oysters  in  tubs  
CANNED  GOODS 

Sardines  ..:  

35-40 
35-40 

•30-35 

35-4° 

Carrots    .'.,.„ 
Celery      .,  ,»«»M^  ' 
Dried  Beans>.    *,.. 
Dried  Corn  ,...'-...  ' 
Dried  Peas  ..  ..Jl^.,.  I 
Onions  

j  *  „  34 
33-34 
32-34 
35-45 
35-45 
3"S-45 

Lemons  ,  „.•  •... 
Oranges  ~  

36-io 
34-36 

Fruits  
Meats  

5-4°  Parsnips":;*."  ""i:.. 

35-4°  Potatoes..  *..  

32  •  33 
32-33 

34-36 

Peaches  ...-.  
p 

32-33 

BUTTER,  EGGS.  ETC. 

Sauerkraut    

35-33 

Watermelons  
MEATS 

32-33 

Butter  .     . 

2-18 

0-35 
o-34 

MISCELLANEOUS 

Cigars.  Tobacco  ' 
Furs.  Woolens,  etc 

35-42 
25*35 

Butterinc  
Cheese...-  

Brined   «..  .- 

35-40 

Eggs  

9  -S2 

Honey  •  

36-40 

Beef,  fresh  _  

33-35 

LIQUIDS 

Hops      ....  

32-34 

Beef,  dried  

36-40 

Beer.  Ale,  etc.,  bbl'd.. 

33-42 

Maple  Syrup,  Sugar  . 

40-45 

Hams,  Ribs'.  Shoulders, 
(not  brined)'  
Hogs  
Lard  _  -  

3°-34 
35-40 

Beer,  etc.,  bottled  ..• 
Cider  t... 
Ginger  Ale  
Wines  ..'.,  

45-50 
30-    o 
35-    o 

Oils     -  
Poultry  dressed,  iced 
Poultry,  dry  picked 
Poultry,  scalded.  .. 
Game,  to  freeze  

35-45 
28  -  30 
26-  28 

20  -  26 
o    5 

Livers  .  

33  -  34 

FLOUR  AND  MEAL 

Game  after  frozen...  .< 

10    28 

Sheep,  Lambs  •-.  . 

32-33 

Buckwheat  Flour  .  ., 

3j-    o 

Poultry  fo  freeze,  

0  '5 

Ox-tails  
Snusage  casings  

30-32  Corn  Meal  .'  
38-45  ;Oat  Meal  :......,. 

36-40) 

Poultry  after  frozen 
Nuts,  in  shell  

35     4° 

Tenderloins,  Butts,  etc.. 

33  -  34  Wheat  Flour  «..  ... 

36-40  Chestnuts  ,  .' 

33     35 

Refrigeration  Required. 

For    rough    estimates    the    following    table    by    Siebel,    based    on 
an  outside  temperature  of  80  to  90°  F.,  is  of  good  practical  use: 

CUBIC  FEET  PER  TON   OF   REFR.    IN  24   HOURS. 
Size  of 

Building  in  Temperature. 

Cubic  Feet. 

1,600 
6,000 
9,000 
13,000 


0° 

100    150 

1,000     600 

10,000     700 

30,000     1,000 

100,000     1,500 


10° 
600 
2,500 
3,000 
5,000 
7,500 


20° 
800 
3,000 
4,000 
6,000 
9,000 


30° 
1,000 
4,000 
6,000 
8,000 
14,000 


20,000 


50' 
3,000 
12,000 
18,000 
25,000 
40,000 


This  table  is  based  on  first-class  insulation;  when  insulation 
poor,  double  amount  of  refrigeration. 

For  accurate  estimates  the  required  refrigeration  has  to  bo 
calculated  as  follows: 

Calculated  Refrigeration, 

By  calculating  the  required  refrigeration  in  a  given  case,  we 
must  consider  the  following  points: 

(a)  To  cool  the  goods  from  the  temperature  at  which  they 
enter  the  storage  room  down  to  the  desired  temperature.  Ex- 
ample, to  cool  30,000  Ibs.  of  fresh  meat  a  day  from  95°  to  35°,  with 
an  outside  temperature  of  85°. 

RI  =  P  (t  —  ti)  s       s  =  spec,   heat  (on  an  average  =  0.8) 
30,000  (95  —  35)  0.8 


24 
=  60,000  units  per  hour. 


GENERAL  COLD  STORAGE.        55 

If  the  goods  are  cooled  below  32°  F.,  that  is,  frozen,  the  specific 
heat  changes.  (See  table  on  Specific  Heat.) 

(b)  To  offset  radiation  through  walls  and  floors. 

The  loss  of  cold  is  the  total  exposed  area  multiplied  with  the 
difference  in  temperature  and  the  respective  factors  of  heat 
transmission,  which  for  average  insulation  can  be  taken  as  3 
units  per  degree  of  difference  in  temperature  in  24  hrs.  (See 
chapter  on  Insulation.) 

Example:    Chill  room,  40  X  50  X  10  =  20,000  cb.  ft. 
Side  walls  of  room  =    1,800  sq.  ft. 

Ceiling  and  floor  =    4,000  sq.  ft.     • 


Total  surface  =    5,800  sq.  ft. 

5,800  (85  —  35)  3 
Ra  =  A  (t  —  ti)  3  =  — 

24 
—  36,250  units  per  hour. 

(c)  To   offset  loss  of  cold   through  opening  of  doors,    etc. 
Calculation    is    approximately    5    to    8%    of    totai    refrigeration 

(small    boxes    considerably    more).      Provide    ante-rooms    or    gang- 
ways. 

R3  =1  approx.   7,850  units  per  hour. 

Loss  through  lights  and  the  presence  of  persons  may  be  calcu- 
lated as  follows: 

Heat  developed  in  one  hour: 

One  workingman   —  500  units. 

One  gas  light  =  3,600  units. 

One  incandescent  light  of  16  c.  p.  =  160  units. 

One  ordinary  caudle  =  450  units. 

Electric  light  preferable,  as  well  as  being  convenient  for  turning 
on  and  off. 

(d)  An   extra   amout   of  refrigeration   is    required,   where   forced 
air  circulation   is  used   and   the   total  air  is   renewed  about   4   to 
6   times  daily.     To  maintain   the   conditions  in   the   room   as   uni- 
formly as  possible,  the  renewal  of  the  air  should  be  continuous. 

The  loss  of  cold  through  air  renewal  depends  upon  the  difference 
of  in  and  outside  temperature,  frequency  of  air  renewal  and 
percentage  of  humidity  of  inner  and  outer  air. 

Example : 

(1)  Refrigr.  r^  to  precipitate  the  difference  in  moisture. 

The  air  leaves  at  35°  and  70%  humidity  and  new  air  enters  at 
85°  and  80%  humidity. 

One  cb.  ft.  of  air  at  85°  and  80%  hum.  contains  13  X  0.8  =  10.4 
grains  of  moisture. 

One  cb.  ft.  of  air  at  35°  and  70%  hum.  contains  2.44  X  0.7  =  1.7 
grains  of  moisture. 

As  one  pound  of  vapor  contains  7,000  grains,  the  latent  heat  of 
one  grain  of  moisture 

1090 

= =  0.15576  units. 

7000 

If  the  air  is  changed  6  times  daily,  it  means 
20,000  X  6 

=  5000  cb.  ft.  of  air  in  one  hour. 

24 

Refrigeration  FI  =  5000  X  0.15576  (10.4  —  1.7) 
=  6780  units. 

(2)  Refrig.  r2  to  cool  the  air  from  85°  to  35°. 

Weight  of  1  cb.  ft.  dry  air  at  35°  and  atm.  press.  =  0.087. 
Spec,  heat  of  air  at  constant  press.  =  0.2375. 


56        GENERAL  COLD  STORAGE. 

r2  =  5000  X  0.087  X  0.2375  (85  —  35) 

=  5000  units. 
R*  =  i-i  +  r2 

=  11,780  units  per  hour. 

This  loss  of  cold  is  reduced  to  about  50%  by  providing  a  heat 
exchanger  between  the  outgoing  and  incoming  air,  consisting  of 
air  ducts  separated  by  thin  sheet  metal  partitions. 

R4  =  5900  units  per  hour. 
Total   amount   of    refrigeration    =  Rx  +  R2  +  R3  +  R4  =: 

R  =  110,000  units  per  hour. 

If  air  at  35°  and  70%  humidity  shall  be  reduced  in  the  cooler 
to  21°  and  70%,  the  reduction  of  temperature  requires  per  cb.  ft. 

=  0.02  (35  —  21)  =  0.28   units. 
And  to  dry  the  air: 

=  0.15576(2.44  X  0.7  —  1.36  X  0.7)  =  0.117  units. 
A  total  of  0.28  +  0.117  =  0.4  units  per  cb.  ft. 

110,000 

Consequently   -          —  =  275,000   cb.    ft.    must   pass    every    hour 
0.4 

275,000 

through  the  cooler,  what  would  correspond  to  -         —  =  nearly 

20,000 

14  air  circulations  of  total  cubic  contents  every  hour. 

The     area  of  main  air  ducts  will  be,  by  assuming  a  velocity  of 

15  ft.  per  second 

275,000 
=  —  —  =  about  5  sq.  ft. 

15  X  3,600 

The  fan  will  require,  assuming  that  0.25  H.  P.  takes  care  of 
35,000  cb.  ft. 

275,000 
—  —        —  X  0.25  =  about  2  H.  P. 

35,000 

As  one  H.  P.  is  equivalent  to  2,565  units,  which  are  directly  in- 
troduced into  the  circulated  air,  we  have  to  correct  the  total 
amount  of  refrigeration  by  2  X  2,565  =  5,130  units. 

110,000  +  5,130  =  115,130  units  per  hour. 
115,130  X  24 


284,000 
=  about  9.4  tons  of  refrigeration  in  24  hrs. 

Piping. 

The  pipes  should  be  so  arranged  as  to  induce  air  circulation  (see 
Fig.  19).  Gutters  and  drip  pans  provided  where  necessary. 

CUBIC  FEET  PER  FOOT  OF  2"  DIE.   BXP.  PIPE. 
Size 

Bldg.  in  Temperature. 

Cub.  Ft.  0°  10°  20°            30°  409  50* 

100     0.5  2.3  3.6             4.5             6.5  9 

1,000     1.8  7  10.6           14  20  33 

10,000     3  10.5  17              22  30  48 

30,000     3.5  14  23              30  42  68 

100,000     4.5  17  28              37  56  100 

These  ratios  are  based  on  first-class  insulation;  when  insulation 
Fig.  19).     Gutters  and  drip  pans  provided  where  necessary. 
No  more  than  1,200  feet  2"  pipe  in  one  expansion. 
For  1"  pipe  use  1.8  times  amount  of  2"  pipe. 
For  1*4"  pipe  use  1.44  times  amount  of  2"  pipe. 
When  using  disks,  multiply  amount  of  pipe  with  4/7. 


GENERAL  COLD  STORAGE. 


57 


c 


[';--> 

P 

->  '  * 

// 


FIG.    19— ARRANGEMENT    OF    COOLING    PIPES    AND    AIR    DUCTS    TO 
INDUCE    AIR    CIRCULATION. 


a,  b,  pipes  on  ceiling;  c,  d,  e,  pipes  on  wall;  f,  h,  pipes  in  overhead  lofts; 
g,  i,  j,  forced  air  circulation. 


58        GENERAL  COLD  STORAGE. 

Brine  Cooling  System, 

For  indirect  expansion  (brine  cooling)  use  1%  times  amount  of 
pipe. 

Brine  Tank. — The  size  of  the  brine  tank  is  calculated  by  allowing 
about  60  cb.  ft.  of  brine  per  ton  of  refr. 

The  amount  of  expansion  pipe  in  the  tank  is  often  taken  equal 
to  the  amount  of  a  submerged  condenser.  For  safe  calculation 
allow  120  to  150  ft.  of  2-inch  pipe  (or  its  equivalent  in  other 
sizes)  per  ton  of  refrigeration  in  24  hrs.  In  case  of  ice-making, 
double  amount.) 

The  coil  and  shell  brine  cooler  is  based  on  15  sq.  ft.  of  pipe 
surface  per  ton  of  refr. 

Brine  Pump. — Velocity  about  60  ft.  per  min.  Builders  usually 
figure  the  area  of  brine  main  by  assuming  one  sq.  inch  per  ton 
of  refr.  and  a  discharge  of  the  pump  =  4  gals,  per  min.  per  ton 
of  refr. 

For  general  cold  storage  purposes  the  direct  expansion  system 
may  be  well  recommended,  provided  that  the  temperatures  of  the 
different  rooms  are  almost  the  same  and  that  the  pipe  runs  are 
short.  Long  runs  are  liable  to  leak  and,  by  discharging  ammonia 
in  the  room,  spoil  the  goods.  Great  care,  therefore,  must  be  taken 
by  having  only  first-class  pipe  work  and  fittings  used.  The  flanges 
must  be  soldered  on  the  pipes,  so  as  to  make  solid  joints,  and 
should  be  made  male  and  female,  so  as  to  prevent  the  lead  gasket 
from  being  blown  out.  If,  however,  the  rooms  are  kept  at  widely 
different  temperatures,  it  is  difficult  to  regulate  the  ammonia  so 
that  it  will  flow  evenly  through  all  the  rooms.  The  reason  of 
this  is  found  in  the  fact  that  ammonia  tries  to  settle  down  in  the 
coldest  place  it  can  find.  If,  for  example,  one  room  is  kept  at 
20  degrees  and  the  other  at  40  degrees  and  both  to  be  cooled  in 
the  same  time  by  the  same  machine,  the  ammonia  has  the  disposi- 
tion to  collect  in  the  pipes  of  the  coldest  room.  If  the  engineer 
in  charge  does  not  watch  carefully,  the  pipes  in  the  coldest  room 
will  fill  with  liquid  ammonia,  and  hardly  any  ammonia  is  left  in 
circulation. 

Forced  Air  Circulation. 

The  cooling  pipes  (direct  or  indirect  exp.)  are  calculated  as 
above.  They  are  arranged  in  a  special  chamber,  which  is  con- 
nected with  the  rooms  to  be  cooled  by  wooden  air  ducts.  A  fan 
or  blower  is  provided  which  draws  the  air  from  the  highest  part 
of  the  room  and  forcing  it  through  the  cooler,  brings  it  in  con- 
tact with  the  cold  coils,  where  it  is  cooled  and  dried.  The  cooled 
air  leaves  the  cooler  and  is  discharged  back  into  the  rooms  from 
which  it  was  taken. 

The  necessity  of  having  two  series  of  coils  for  successful,  con- 
Mnued  operation,  and  the  trouble  of  thawing  off  one  of  them  and 
removing  the  drip-water,  led  to  the  construction  of  the  "wot 
cooler."  The  refrigerating  coils  are  arranged  vertically  with  a 
gutter  provided  on  the  top  of  each  to  hold  the  brine.  The  brine 
is  showered  over  the  pipes  and  collects  in  a  pan,  from  which  it 
is  drawn  by  a  small  centrifugal  pump  and  returned  to  the  gutter 
to  be  showered  again  over  the  pipes.  The  whole  apparatus,  which 
usually  stands  over  the  cold  room,  is  enclosed  in  a  well  insulatad 
chamber. 

Instead  of  pumping  brine  over  the  expansion  coils,  Madison 
Cooper  places  Calcium  Chloride  in  the  gutters  above  the  pipe  coils. 
This  Calcium,  being  highly  hygroscopic,  absorbs  the  moisture  of 
the  air  and  forms  a  strong  brine,  which  trickles  over  the  pipes. 

The  construction  of  air  coolers  must  be  so  that  a  duct  from 
the  open  air  to  the  suction  side  of  the  fan  is  provided,  through 
which  fresh  air  can  be  drawn  and  led  into  the  cool  room  when 


GENERAL  COLD  STORAGE.       59 

required.  This  duct  can  also  be  made  use  of  if  the  cold  room  is 
needed  in  winter,  when  cold  air  from  outside  alone  is  blown  into  it. 

In  order  to  be  able  to  warm  the  air  in  severe  winter  weather  a 
series  of  steam  coils  is  arranged  on  the  delivery  side  of  the  fan. 
This  method  has  not  been  found  to  answer  well  in  very  cold 
weather,  because  the  air  blown  into  the  cold  room  through  the 
lower  air  duct  rises  quickly  upward  and  is  led  away  by  the  upper 
duct  without  producing  much  effect,  and  the  air  remains  almost 
unchanged  in  the  lower  part  of  the  room.  To  obtain  a  sufficient 
supply  of  air  for  a  very  cold  winter  day  there  must  be  a  third  air 
duct  laid  on  the  floor  of  the  cold  room  for  carrying  off  the  warm 
air  at  the  same  time  that  some  passes  out  through  the  suction 
duct. 

The  air  ducts  are  generally  made  of  galvanized  iron,  which 
have  to  be,  where  the  ducts  run  through  the  engine  house  or  other 
warm  places,  properly  insulated  or  they  are  made  of  tongued 
and  grooved  boards,  saturated  with  chloride  of  zinc  or  protosul- 
phate  of  iron.  The  American  Linde  Company  gives  the  following 
rules: 

The  boards  are  planed  smooth  and  laid  close  together  and  are 
supported  by  knee  frames  about  2"  X  1"  every  10  feet  and  fillets 
attached  to  the  side  wall  and  ceiling.  The  inside  of  the  ducts 
is  left  perfectly  smooth  to  avoid  friction  and  eddy  currents.  The 
air  is  admitted  and  discharged  through  10"  X  6"  openings,  con- 
veniently spaced  along  the  ducts,  the  deliveries  being  in  the  bot- 
tom of  the  supply  ducts  and  the  suction  duct  holes  on  the  side. 
The  openings  are  fitted  with  hardwood  doors,  sliding  in  rebated 
runners,  and  afford  an  opportunity  for  regulating  the  amount  of 
air  and  consequently  the  degree  of  cold  in  any  room,  irrespectire 
of  another,  without  the  necessity  of  altering  the  speed  of  the 
fans  or  the  temperature  of  th©  brine. 

NOTES  ON  GENERAL  COLD  STORAGE: 


Brewery  Refrigeration 

The    process    of    making    beer    briefly    consist    of    malting    and 
brewing.     Malting  consists  of  : 

1.  Steeping  the  barley  in  water  to  supply  moisture  enough   to 
cause  it  to  germinate,  when  it  is  called  "malt." 

2.  Drying  the  malt  on  a  kiln  by  hot  air. 
Brewing  consists  of : 

1.  Mashing  or  mixing  the  malt,  after  it  is  ground,  with  water, 
the  mixture  being  called  "wort." 

2.  Boiling  the  wort  in  the  brew  kettle. 

3.  Cooling  the  hot  wort  in  the  beer  cooler. 

4.  Fermenting  the  same  in  the  fermenting  tubs. 

5.  Racking  and  storing. 

The   boiling   beer   wort,    coming  from  the   brew   kettle,   Fig.    20, 


ZLffl 


FIG.  20— DIAGRAM  OF  BREWING  BEER. 

is  pumped  into  the  settling  tank,  from  where  it  flows  into  a 
cooling  vat,  exposed  to  the  atmosphere  (usually  on  the  roof), 
where  the  wort  is  cooled  down  to  about  110°  F. 

Being  cooled  to  40°  F.  (ale  to  55°)  in  the  beer  cooler,  ic  enters 
the  fermenting  tubs,  where  the  heat  developed  by  the  fermenta- 
tion of  the  wort  is  withdrawn  by  ATTEMPORATORS. 

Refrigeration  is  applied!  to,  (a)  beer  cooler,  (b)  attemp orators, 
(c)  cellars  and  hop  room. 

Beer  Cooler. 

The  beer  cooler  (Baudelot  cooler)  consists  of  two  sections,  the 
upper  section,  through  which  well  or  hydrant  water  flows,  which 
cools  the  wort  down  to  70°  or  60°  Fahr.,  and  the  lower  section, 
which  cools  the  wort  down  to  40°  Fahr.  by  means  of  cooled  brine 
or  direct  expansion  pipes  (sometimes  ice  water). 

Pipes  are  of  2-inch  polished  iron  pipe.  The  cooling  which  is 
imparted  to  them  by  the  wort  prevents  rusting.  Pipes  covered 
with  copper  are  sometimes  rendered  non-conducting  by  lack  of 
contact  between  pipe  and  copper  covering. 


BREWERY   REFRIGERATION. 


61 


DIMENSIONS  OF  LOWER  SECTION  OF  BEER  COOLER  USING 

DIRECT  EXPANSION. 
Final  Temperature  of  Wort  40°  Fahr. 

Twenty-four  pipes — Initial  temp,  of  wort  90° — 

20  ft.  long  for  100  bbls.  per  hour  require  120  ton   refr. 
1G    "      "       "       80     "         "        "  "  95     " 

12    "      "       "       60     "         "       "  "  70     " 

Twenty  pipes — Initial  temp,  of  wort  80° — 

20  ft.  long  for  100  bbls.  per  hour  require  100  ton   refr. 

16    "      "       "       80     "         "        "  "  75     " 

12    "      "        "       60     "          "        "  "  58     "  "     " 

Sixteen  pipes — Initial  temp,  of  wort  70° 

20  ft.   long  for  100  bbls.  per  hour  require     70  ton   refr. 
16    "'     "       "       80     "         "       "  "  57     " 

12    "      "       "       60     "         "       "  "  43     " 

Twelve  pipes — Initial  temp,  of  wort  60° — 

20  ft.  long  for  100  bbls.  per  hour  require     48  ton  refr. 
16    "      "       "       80     "         "       "  "  39     " 

12    "       "        "        60     "          "        "  "  30      " 

These   figures   are   based   on   five   barrels   of   wort   per   hour  per 
foot  of  pipe. 

If  the  cooling,  as  usually,  is  to  be  done  in  three  hours,  allow 
only  one-third  of  the  pipe. 

One  barrel  equals  32  gallons,  or  265  Ibs. 

In  case  of  brine,  add  20  per  cent,  pipe  surface. 


UPPER  PORTION  OP 

BAUDELOT  COOLED  BY  WELL, 

OR  HYDRANT  WATER 


Baudelot  Cooling  for  Beer  Wort 
BRINE  SYSTEM.. 


FIG.   21. 


One   hundred  barrels   of  wort  require   125   Ibs.   of  cooling  water 
at  56°  on  upper  section. 
One  ton  refrigeration  required  for  twenty-five  barrels  of  beer. 


62 


BREWERY    REFRIGERATION . 


Attemporators. 

The  attemporator  coils  are  suspended  (mostly  with  swivel  joints) 

in  the  fermenting  tubs.  They 
are  made  of  iron,  brass  or 
copper,  and  of  IVi,  1%  or  2- 
inch  size.  Diameter  of  coil, 
abovit  two  thirds  of  tub. 

Attemporators     in     cylinder 
form  are  usually  made  in  two 


/ftternfora/or     Tank. 


/Itttmporator     Pumft 


FIG.    22—  ATTEMPERATOR   SYSTEM. 

18"  diam.    X   18"  high,  cooling  surface,  14%  sq.  ft. 

36"  diam.   X  30"  high,  cooling  surface,  47  sq.  ft. 

100  barrels  of  wort  require  12  square  feet  of  pipe  surface 
(19  feet  2-inch  pipe). 

The  refrigeration  is  produced  by  means  of  cooled  fresh  water 
(safer  in  case  of  leaks)  or  brine  (cheaper)  circulated  through  the 
attemporators  at  about  34°  Fahr. 

Expansion  pipe  in  attemperator  tank  about  12  square  feet  of 
pipe  surface  per  100  barrels  ivort. 

Provide  standpipe  and  pump  regulator. 

Piping  of  Cellars  and  Hop  Room. 

RATIOS    FOR    ALB    BREWERIES. 
2"  pipe  direct  expansion  with  14"  disks  per  foot. 


Temp,  of 
Room.  Room. 

Fermenting    50°— 6O° 

Vat  or  Ale  Stor. .   45°— 50° 

Ale  Chip 45°— 50° 

Ale  Chip  and 
Carbonating    .  ..  33°— 35° 

Carbonating    32°— 35° 

Stock  Ale 50°— 55° 

Racking    32°— 34° 


Size  of  Room  in  Cubic  Feet. 
10,000     15,000      20,000     30,000 
1:50 
1:40 


1:40 

1:30 
1:25 
1:50 
1:20 


1:50 
1:40 
1:45 


1:55 
1:42 
1:50 


1:60 
1:45 
1:55 


1:32 
1:28 
1:50 
1:23 


Starting 
Yeast   . 


50°— 55° 
32° 


NO  DISKS. 
1,000       2,000 
1:15         1:16 
1:6  1:7 


1:35 
1:30 
1:55 
1:25 

3,000 
1:18 
1:8 


1:40 
1:35 
1:58 
1:28 

4,000 
1:20 
1:10 


40,000 
1:70 
1:50 
1:60 

1:45 
1:3-8 
1:60 
1:30 

5,000 
1:22 
1:12 


BREWER Y   REFRIGERA T10N. 


PIG.  23— MODERN  BREWERY  EQUIPPED  WITH  REFRIGERATING 

PLANT. 

RATIOS    FOR    LAGER    BEER    BREWERIES. 
2"  pipe  direct  expansion  with  14"  disks  per  foot. 


Temp,  of 

Size  of  Room  in  Cubic  Feet. 

Room. 

Room. 

10,000 

15,000 

20,000 

30,000 

40,000 

Starting  tub  

34°—  36° 

1:23 

1:24 

1:25 

1:25 

1:25 

Fermenting   

34°—  36° 

1:23 

1:24 

1:25 

1:25 

1:2;> 

Storage    (Rime).  . 

32°—  33° 

1:38 

1:40 

1:43 

1:45 

1:47 

Chip  Cask  (Spa). 

32°—  34° 

1:40 

1:43 

1:45 

1:47 

1:50 

Racking    

34°—  36° 

1:23 

1:24 

1:25 

1:28 

1:80 

Mop     Storage. 


32' 


3,000 
1  :20 


4,000 
1  :22 


5,000 
1.23 


6,000        8,000 
1  :24        1  :25 


64  BREWERY   REFRIGERATION. 

Example:  Ratio,  1:23  means  —  1  foot  of  pipe  for  23  cubic  feet 
of  room. 

Add  75%  more  pipe  if  without  disks. 

Weight  of  1  foot  2  inch  pipe,  with  disk  and  ice,  about  75  pounds, 
length  =  20  feet. 

No  more  than  1,200  feet  2  inch  pipe  in  one  expansion   (approx.). 

One  ton  refrigeration  for  120  feet  2  inch  expansion  pipe. 

Wherever  convenient,  place  piping  on  the  ceiling. 

Storage  and  Chip  Cask. — Piping  may  be  placed  on  the  ceiling. 

Fermenting  Room. — Place  piping  over  aisles  or  passageways,  so 
as  not  to  drip  into  the  fermenting  tubs. 

Racking  Room. — Piping  may  be  placed  on  the  ceiling  and  as  much 
as  possible  about  the  door,  to  take  up  the  outside  heat  as  it  enters. 

Hop  Storage.- — Piping  must  be  placed  in  a  bank  at  the  side  of 
the  room,  so  that  all  moisture  can  be  easily  drained  away  (forced 
air  cooling  preferred). 

Brine  vs.  Direct  Expansion. 

It  is  customary  to  shut  off  all  rooms  from  the  pipe  line  during  the 
short  period  of  time,  usually  3  hours,  that  the  wort  is  cooled. 
Since  this  represents  the  maximum  amount  of  work  required  from 
the  refrigerating  machine,  its  capacity  is  usually  figured  on  the 
amount  of  work  done  in  cooling  a  given  quantity  of  hot  beer  wort 
within  3  hours. 

Hettinger  claims  that,  in  case  the  wort  is  cooled  by  the  brine 
system,  only  one-eighth  of  the  refrigerating  capacity  is  needed 
against  that  required  in  the  case  of  direct  expansion,  because  the 
cooling  of  the  brine  itself  is  extended  over  the  entire  24  hours. 
No  regulation  of  the  expansion  valves  is  required,  since  the  tem- 
prature  of  the  brine  in  the  tank  will  only  be  raised  7.3  degrees 
F.  during  the  entire  period  of  cooling  the  wort,  the  capacity  of 
the  brine  tank,  being  four  times  as  great  as  the  amount  of  the 
beer  cooled. 

A  refrigerating  machine  using  the  brine  system  has  to  have 
double  the  capacity  to  a  day's  work  in  12  hours  that  would  be 
required  to  do  the  work  in  24  hours. 

Hettinger  tries  to  disprove  this  by  an  example.  He  assumes  a 
brewery  plant,  equipped  with  a  250-barrel  beer  kettle,  the  output 
being  half  lager  and  half  stock  and  lively  ale  and  the  brewing 
of  ale  and  lager  beer  being  done  alternately.  Total  space  of  the 
different  rooms  =  106,801  cubic  feet.  Allowing  7,000  cubic  feet 
for  1  ton  of  refrigeration  in  21  hours,  the  required  number  of 
tons  of  refr.  =  15.26  tons.  Heat  of  fermentation  in  21  hours  = 
8  tons. 

Cooling  the  beer  through  a  racking  cooler,  allowing  6°  in  8 
hours  =  4  tons.  This  means  that  the  refrigerating  machine  will 
do  52  tons  of  refr.  during  3  hours,  and  about  26  tons  during  tho 
remaining  21  hours  on  the  day  lager  beer  is  brewed.  The  next 
day  when  ale  is  brewed,  the  refrigeration  required  for  cellars, 
fermenting  room  and  racking  room  will  be  the  same,  that  is,  26 
tons  in  21  hours.  The  ale  storage  does  not  require  any  refrigera- 
tion whatsoever. 

The  required  capacity  of  the  refrigerating  machine,  assuming 
that  the  ale  will  be  cooled  down  14  degrees  in  less  than  2.5  hours 
and  the  wort  having  a  strength  of  15  per  cent  Balling:  (259  X 
250  X  14  X  10  X  1.0614  X  0.9)  -h  284,000  =  30.49  tons  of  re- 
frigeration. 

By  doing  the  same  amount  of  work  with  the  brine  system,  in  24 
hours,  the  calculation  in  tons  will  be  as  follows: 

Cooling  125  barrels  of  wort  for  lager 3.25 

Cooling  cellars  and  rooms  13.35 

Developing  heat  of  250  barrels  of  ale  and  lager 7.00 


BREWERY   REFRIGERATION.  65 

Chilling  125  barrels  lager  beer  for  racking 1.34 

Cooling  125  barrels  of  wort  for  ale 1.50 


Total   26.44 

So  that  a  machine  of  26.44  tons  is  required  to  perform  this 
amount  of  work  in  24  hours,  or  a  machine  of  52.88  tons  to  do  the 
work  in  12  hours. 

250  barrels  is  substituted  for  125  barrels  of  ale  and  125  barrels 
of  lager  because  the  work  of  the  refrigerating  machine,  owing 
to  the  brine  system,  is  extended  over  48  hours,  figuring  one-half 
brew  of  ale  and  one-half  brew  of  lager,  the  machine  being  cal- 
culated to  run  at  the  same  speed  and  back  pressure  during  the 
brewing  of  lager  and  ale. 

NOTES  ON  BREWERY  REFRIGERATION: 


Packing  House  Refrigeration 


MODERN    PACKING    HOUSE    EQUIPPED    WITH    FORCED    AIR 
CIRCULATION. 

Refrigeration  should  be  produced  by  cold,  dry  air,  which  cir- 
culates freely  around  the  meats,  especially  in  the  chill  rooms, 
where  the  steam  from  the  fresh  killed  animals  and  the  foul  gases 
have  to  be  removed,  so  as  not  to  affect  the  goods  and  the  in- 
sulation. 

Forced  air  circulation  may  cause  a  little  more  loss  in  weight 
in  meat,  but  it  is  the  soundest  when  viewed  bacteriologically. 

Recently  a  store  room  with  direct  expansion  became  invaded 
with  phosphorescent  bacteria.  These  bacteria  produced  a  brilliant 
phosphorescence  on  a  great  many  quarters  of  beef  and  carcases 
of  mutton.  The  temperature  of  the  room  ranged  about  35  to  40 
degrees  F.  The  germs  can  grow  even  at  much  lower  temperatures, 
and  they  produce  poisonous  properties  in  meat. 

To  exterminate  this  bacillus  from  a  room,  the  doors  must  be 
open,  all  ice  and  snow  scraped  away,  and  the  pipes  and  the  walls, 
floor  and  ceiling  washed  with  solutions  of  lime,  containing  chloride 
of  zinc.  This  zinc  should  exist  in  the  wash  in  the  proportion  of 
1  to  1,000.  All  meat  that  has  become  infected  should  be  destroyed, 
as  it  is  unfit  for  food. 

Almost    all    European    and    Australian    packing    houses    are    re- 


PACKING  HOUSE  REFRIGERATION.         67 

frigerated  on  the  forced  air  cooling  system  with  wet  air  coolers, 
which  provides  for  the  continuous  ventilation  of  the  chambers, 
and  the  purification  of  the  air  contained  in  them.  Under  these 
conditions  there  is  no  chance  of  the  growth  of  bacteria  which 
would  be  detrimental  to  health. 

Refrigeration  Required. 

A.  Storage  rooms,  which  is  estimated  like  "General  Cold  Storage." 

B.  Chilling   rooms,    either   calculated   like    General   Cold   Storage 
or  roughly  estimated. 

One  ton  rep'.   (24  hrs.)   for  each  of  the  following  duties: 

15  to  24  hogs  of  250  pounds  each. 

5  to  7  beeves  of  700  pounds  each. 

45  to  55  calves  of  90  pounds  each. 

50  to  70  sheep  of  75  pounds  each. 

Hog  chill  rooms  to  be  reduced  to  32°   F.   in  24  hrs. 

Beef  chill  rooms  to  be  reduced  to  32°  F.  in  36  hrs. 

Chilling  rooms  to  have  ventilators  on  ceiling  to  allow  steam  and 
gases  to  escape,  after  which  same  have  to  be  closed. 

Space  required.— Nine  sq.  f.  per  beef,  12  ft.  high.  Two  sq.  ft. 
per  sheep,  8  ft.  high.  Meat  rails  about  27"  apart. 

Piping  to  be  estimated  like  General  Cold  Storage,  with  an 
addition  of  13  ft.  2"  direct  cxpans.  per  ox,  and  6  ft.  2"  pipe  per 
hog. 

Piping  to  be  arranged  in  overhead  lofts. 

C.  Freezing  Rooms.     (Temperature  10°  F.  and  below.) 
Refrigeration    is    calculated    like    General    Cold    Storage   with    an 

addition  of  one  ton  refr.  per  ton  of  meat. 

Piping  estimated  like  General  Cold  Storage,  with  an  addition  of 
30  ft.  2"  direct  expans.  pipe  per  ox,  and  15  ft.  2"  per  hog. 

NOTES  ON  PACKING  HOUSE  REFRIGERATION: 


Can  Ice  Plants 


Capacity  of  Plant. — The  ice  making  capacity  is  far  below  the 
refrigerating  capacity,  as  we  have  to  cool  the  water  first  from 
the  ordinary  temperature  to  32°,  and  from  there  to  the  tempera- 
ture of  the  brine.  An  allowance  of  6  to  12  per  cent,  loss  has  to 
be  made,  due  to  radiation  in  freezing  tank,  pipes,  etc.  This 
would  leave  60  per  cent,  of  the  refrigerating  capacity. 

Ref r.   tons    5         10    20    35    50    75    100    150    220    300    500 

Ice,  tons  21/2       5    12    20    30    45      60      90    130    180    300 

Time  of  Freezing. 

The  time  of  freezing  depends  on  the  temperature  of  the  brine 
and  the  thickness  of  the  ice.  The  following  table  is  calculated 
by  A.  Siebert,  on  the  assumption  that  the  time  of  freezing  is 
proportional  to  the  square  of  the  thickness. 

FREEZING  TIMES  FOR  DIFFERENT  TEMPERATURES  AND  THICK- 
NESSES OF  CAN  ICE. 


Thickn'ss. 

1  in. 

2  In. 

1.28 
1.40 
1.56 
1.75 
2.00 
2.32 
2  80 
3  50 

3  in. 

4  in. 

Sin. 

6  in. 

7  in. 

8  in. 

9  in. 

10  in. 

11  in. 

38.5 
42.3 
47  0 
53.0 
60  ft 
70.5 
84  7 
106.0 

12  in. 

Temp.  10° 
,       12° 
14° 
16° 

18° 
20° 

5 

0.32 
0.35 
0.39 
0.44 
•0.50 
0.58 
0.70 
0.88 

2.86 
3.15 
3  50 
3.94 
4.50 
5.26 
6.30 
7.86 

5.10 
5  60 
6  22 
7.00 
8.00 
9.30 
11.2 
14.0 

8  00 

8  7n 

9  70 
11  0 
12.6 
14  6 
17.6 
21,0 

11.5 
12  6 
14.0 
!5.8 
18.0 
21.0 
25.2 
31  5 

15.6 
17  3 
19.0 
21.5 
24.5 
28.5 
34.3 
42.8 

20.4 

25  0 
2ft  0 
32  0 
37.3 
44.8 
560 

25.8 
28  4 
31-.  s 
35  6 
40.5 
47.2 
5ft  7 
71.0 

31.8 
35-0 
390 
43  7 
50.0 
58  3 
70  0 
87.6 

45.8 
50.4 
56  0 
63  0 
720 
84.0 
100  0 
12i>.  0 

The  sizes  of  the  cans,  most  in  use,  are  given  as  follows  : 


- 

Weight  of 

c«  blocks. 

Thickn« 

Time  of  freezing. 

Nominal. 

Actual. 

Sides. 

Bottom. 

15°  brine       t8°  brine. 

6     12  x  26" 

50 

56 

20" 

20' 

tS  hrs        20  hrs. 

8     16  x  32 

100 

110 

18" 

16 

30    "         36    " 

8     16x42" 

150 

165 

18" 

16 

30    "         j6    " 

11    J32x32" 

200 

220 

18' 

14 

5°    "         60    " 

11     22x44" 

300 

315 

16" 

14 

50    "        60    " 

11     22x57" 

400 

415 

16 

14" 

50    "        60    " 

The  temperature  of  the  brine  is  about  10°  higher  than  the  am- 
monia in  the  expansion  coils.  By  maintaining  a  good  brine  agita- 
tion, the  temperature  may  be  lowered  a  few  degrees. 

Back  pressure,  Ibs.  (gauge) 5       10       15       20       25       30 

Brine    temperature    °F —  5         0       10       15       20       25 

Freezing  Tanks. 

Expansion  Pipe. — By  good  brine  agitation   and  short  expansions 

about  85  to  100  square  feet  of  pipe  per  ton  of  ice  will  be  sufficient. 

With  a  low  back  pressure  the  amount  of  pipe  may  be   reduced. 

The  greatest  efficiency  is  obtained  with  horizontal  coils.     In  the 

case  of  vertical  coils,  top  expansion  is  given  the  preference. 

Amount  of  pipe  per  ton  of  ice. 

15°  brine.  18°  brine. 

400  ft.  of  1"       pipe  450  ft.  of  1"       pipe 

320  ft.  of  1%"  pipe  360  ft.  of  1%"  pipe 

270  ft.  of  iy2"  pipe  310  ft.  of  iya"  pipe 

210  ft.  of  2"       pipe  240  ft.  of  2"       pipe 

Greatest  length  of  one  expansion  is  1,200  ft. 

Brine  Circulation. — The  brine  is  generally  kept  in  motion  by  a 
propeller,  driven  by  belt  or  direct  connected  to  electric  motor. 


CAN  ICE  PLANTS. 


FKJ.  24. 


I 

'l 

1 

I 

1  o 

IE 

r  T 

I    a 

. 

\  \ 

5         l  -U1 

CAN  ICE  PLANTS. 


In  tanks  up  to  10  tons  use  a  12"  propeller  at  225  rev.  per  minute; 

in  tanks  from  10  to  25  tons  use  an  18"  propeller.     In  larger  tanks 

use  two  propellers,  or,  still  better,  a  centrifugal  pump. 
Allow  7^4  IDS.  of  salt  per  cb.  ft.  of  tank.     (See  chapter  on  brine.) 
Size. — The  size  of  the  tank  depends  on  the  size  of  the  cans,  time 

of  freezing  and  size  of  expansion  pipe. 

The  following  table  is  based  on  18°  brine  and  2"  expansion  pipe: 
5-TON  TANK. 


Weight 
of  blocks. 
100  Ibs. 
150     " 
300     " 


150  Ibs. 

300     " 


150  Ibs. 
200  " 
300  " 

200  Ibs. 
300  " 


Number  of  cans. 

19  X     8  =  152 

13  X     8  =  104 

14  X     6  =    84 

10-TON   TANK. 

20  X  10  =  200 
22  X     8  =  176 

15-TON  TANK. 

30  X  10  =  300 
38  X  10  =  380 
25  X  10  =  250 

20-TON   TANK. 
42  X  12  =  504 
34  X  10  =  340 


Size  of  tank. 
37'-  0  X  10'-4  X  36" 
26'-  0  X  10' -4  X  46" 
34'-  2  X     9'-8  X  4'-0 


40'-  4  X  12'-6  X  46" 
49'-10  X  12' -S  X  4'-0 


58'-  0  X  12'-6  X  46" 

87'-  7  X  15'-0  X  36" 

58'-  7  X  15'-0  X  4'-0 

96'-  4  X  17'-8  X  36" 

78'-  7  X  15'-0  X  4'-0 


Ice  Storage. 

By  calculating  the  size  of  the  ice  storage  room  we  assume  that 
50  cubic  feet  of  ice,  as  usually  stored,  equal  one  ton. 

Storage  and  ante-room  have  to  be  piped.  The  refrigeration  and 
amount  of  piping  can  be  calculated  after  the  rules  applying  for 
General  Cold  Storage.  Frequently  a  ratio  of  1  :14  to  1 :20  is  taken 
for  2"  direct  expansion  and  a,bout  one-third  to  one-half  more 
for  brine  piping.  Pipes  to  be  placed  on  ceiling. 

The  room  should  be  well  insulated  and  be  provided  with  proper 
ventilation  from  the  highest  point  and  have  thorough  drainage. 


SLIDE  DOOR  ON  TANK  ROOM 
SIDE  OF  PARTITION 


.IDING  PU<JK          .^*  /       ,->•'  % 

.  \   (^    .  ->^l  C  E  D  U  M  P       T  ANJfrvOO* 

5fe_ 


ELEVATION 


FIG.  25— DETAILS  OF   SLIDE   DOOR   ON  TANK   ROOM. 

Cost  of  Ice. 

The  cost  of  ice  varies  considerably  with  the  size  of  the  plant, 
the  price  of  coal  and  other  items. 

The  following  table  gives  an  approximate  estimate.  But  necessary 
alterations  for  price  of  coal  and  addition  for  cost  of  delivery,  in- 
terest and  other  things  must  be  made  in  each  case,  which  may 
increase  the  total  cost  of  ice  from  20  per  cent,  in  small  plants 
to  50  per  cent,  in  large  plants. 


CAN  ICE  PLANTS. 


The  table  shows  cost  of  ice  put  in  the  ice  house  ready  to  sell. 


APPROXIMATE  COST  OF  OPERATING  ICE  FACTORIES 


1 

§>; 

si. 

fe 

S 

it 

get 

tter  or 
ist  $2.50 
day. 

h* 

H 
»'5    , 

I! 

n 

a 

1* 

||-o 
•So 

W  S^ 

35  §. 

II1 

ol® 

•~|! 

5* 

tf 

1 

^ 

2' 

IS 

£ 

elf 

1° 

O  be 

& 

1 

i 

l 

$1.50 

j 

$1.00 

900 

$1.35 

.$0.50 

$4.35 

$4.35 

2 

i 

1  50 

i 

1  00 

1,500 

2.25 

0.50 

5.25 

2.63 

3 

2.00 

i 

1  00 

1,800 

2.70 

0.50 

6^20 

2.10 

5 

2.00 

1 

$1.50 

2 

2.00 

2,500 

3.75 

.00 

10.25 

2.05 

74 

2.  CO 

1 

1.50 

1 

$1.50 

2 

2.00 

. 

3,200 

4.80 

.25 

13.05 

1.74 

10 

2.50 

1 

.50 

2 

3.00 

2 

2.00 

3,600 

5.40 

.25 

15.65 

1.57 

15 

2.50 

1 

.50 

2 

3.00 

3 

3.00 

5,000 

7.50 

.50 

19.00 

1.27 

18 

i 

2.75 

1 

.50 

2 

3.00 

3 

3.00 

5,500 

8.25 

.80 

20.30 

1.15 

20 

2 

4.50 

1 

.50 

2 

3.00 

3 

3.00 

6,000 

9.00 

2.00 

23.00 

1.15 

25 

2 

5.00 

] 

.50 

o 

3.00 

4 

4.00 

. 

7,500 

11.25 

2.50 

27.25 

1.09 

30 

2 

5.00 

2 

3.00 

2 

3.00 

4 

4.00 

9,000 

13.50 

3.00 

31.50 

1.05 

35 

2 

6.00 

2 

3.00 

2 

3.00 

5 

5.00 

10,500 

15.75 

3.50 

36.25 

1.03 

40 
50 

2 

2 

6.00  2 

6.50   2 

3.00 
3.00 

2 
3 

3.00 
4.50 

5 
6 

5.00 
6.00 

[  $2  50 

12.COO 
15,000 

18.00 
22.50 

4.00 
5.00 

39.00 
50.00 

1.00 
1.00 

60 

2 

7.00   2 

3.00 

4 

6.00 

7 

7.00 

2  50 

18,000 

27.00 

6.00 

58.50 

1.00 

70 

2 

7.50   2 

3.00 

5 

7.50 

8 

8.00 

2.50 

21,000 

31.50 

7.00 

67.00 

.99 

80 

2 

9.00   2 

3.00 

5 

7.50 

10 

10.00 

1   5.00 

24,000 

36.00 

8.00 

78.50 

.98 

90 

3 

10.00   2 

3.00 

6 

9.00 

11 

11.00 

}   5.00 

27,00040.50 

9.00 

87.50 

.96 

100 

3 

lO.OOl  2 

3.00 

7 

10.50 

12 

12.00 

!    5.00 

30,000(45.00 

10.00 

95.50 

.95 

Coal  Consumption. 

The  coal  consumption  depends  on  the  size  of  plant,  kind  of 
engine,  temperature  of  feedwater  and  quality  of  coal.  The  fol- 
lowing table  is  based  on  an  evaporative  capacity  of  steam  boilers 
of  10  Ibs.  of  water  per  Ib.  of  coal.  For  other  ratios  the  coal  con- 
sumption changes  in  direct  proportion. 

f    4  tons  of  ice  in  a       1  ton  ice  plant. 


One  ton 
of  coal  for 


10 
25 
50 

100 


large  plants  using  evaporators. 
Water  Consumption. 

Water  is  greatly  economized  in  a  can  ice  plant,  as  the  same 
water  is  used  first  over  the  ammonia  condensers,  then  in  the  steam 
condenser  and,  if  it  is  of  good  quality,  as  feed  water  for  the  steam 
boilers.  It  leaves  the  boilers  in  the  form  of  live  steam  to  drive 
the  engines,  the  exhaust  steam  of  which  is  condensed,  purified 
and  used  as  the  water  from  which  the  ice  is  made. 

It  is  evident  that  the  colder  the  water  the  less  will  be  needed. 
An  ice  plant  should  always  have  a  reliable  supply  of  four  to  six 
gallons  of  water  per  minute  for  every  ton,  of  ice. 

WATER    CONSUMPTION     PER    TON    OF    ICE. 
Temperature  of  Water. 

Over  ammonia  condensers 55° 

Entering  steam  condensers 80° 

Leaving  steam  condensers '. 125° 


60° 


125C 


70° 

90° 

125° 


80° 

95J 

125° 


Gallons  per  minute 4         4.5       5.15  6 

Note.— For  every  5  degrees  increase  in  temperature  of  the  cooling 
water  the  coal  consumption  increases  8  per  cent.,  if  the  quantity 
of  the  water  remains  the  same. 


Distilling  Apparatus. 


The  exhaust  steam  from  the  engine  and  pumps  is  generally  used 
to  supply  the  distilled  water.  The  deficiency  in  supply,  which 
increases  with  the  size  of  the  plants,  is  taken  direct  from  the 
boiler. 

The  steam  has  to  be  deprived  of  the  oil  and,  after  being  con- 
densed, is  subjected  to  a  purifying  process  before  it  is  allowed 
to  go  into  the  cans.  It  is  impossible  to  give  any  rules  for  size 
and  number  of  filters  required  on  different  plants,  as  it  may  be 
necessary  to  treat  the  water  specially  according  to  the  quality 
of  the  water  in  the  locality. 

The  usual  course  of  distilling  and  filtering  is  as  follows  :  Engine, 
grease  separator,  steam  condenser,  skimmer  and  reboiler,  charcoal 
filter,  storage  tank. 

Grease  Separator. 

These  work  on  the  principle  that  the  steam  strikes  with  great 
force  against  surfaces  and  deposits  the  oil. 

Linde's  grease  separator  consists  of  a  vertical  cylindrical  tank 
with  an  upright  spiral  partition  in  the  interior.  The  steam  enters 
near  the  bottom  and  strikes  against  this  baffle  plate  where  its 
speed  is  reduced  to  one-fifteenth  of  the  initial  speed.  The  oil 
collects  at  the  bottom  and  is  drawn  off. 

Baldwin's  grease  separator  is  a  cylindrical  tank,  either  hori- 
zontal or  vertical,  filled  to  about  one-fourth  with  water.  The 
steam  strikes  against  the  water  surface  and  deposits  the  oil. 
Baffle  plates  assist  this  process.  These  separators  have  proved 
very  efficient. 

"York's"  grease  separator  is  placed  in  the  exhaust  steam  pipe 
in  line  with  the  pipe.  The  inlet  nozzle  is  surrounded  by  corru- 
gated baffle  plates  through  which  the  steam  must  pass  and  whicn 
effectually  separate  the  oil. 

In  the  coke  filter  the  steam  has  to  pass  through  a  large  mass  of 
coke,  which  is  well  adapted  for  extracting  the  oil  from  the  steam. 


"De  Lot  Very-Mr    C,  Ate  ft /far 


im 


Aojtrf- 


21  "/3. 


/f 


31 


ZO 


&/''* 


30 


30 


6.0 


9o 


10 


9/ 


36 


tt'/l 


130 


10 


Steam   Condenser. 

1.    Amount    of    Cooling    Water    per    ton    of    distilled    water    in 
24  hrs. 

2000  X  960 

P  = 

t-ti 

ti  =  initial  temp,  of  water,  t  =  final  temp,  of  water. 
960  =  latent  heat  of  steam. 


DISTILLING  APPARATUS. 


73 


Example  :    ti  =  85°  F.,  t  =  125°  F. 

2000  X  960 
P  =  — =  48,000  Ibs.  in  24  hrs. 


125  —  85 
48,000 


=  4  gals,  per  min. 


24  X  60  X  8.3 

2.    Cooling  Surface  in  sq.  ft.  per  ton  of  water  in  24  hrs. 
2000  X  960 

S  = 

(ti  —  t)  n  X  24 

t  =  mean  temp,  of  cooling  water, 
ti  =  average  temp,  in  condenser  (about  210°  F.). 
n  —  heat  transmission  per  sq.  ft.  per  hour  per  degree  of  differ- 
ence in  temp,  (about  200  to  500). 
Example  (continued)  : 
2000  X  960 

S  =  —         =  about  4  sq.  ft. 

(210  —  105)  200  X  24 
For  practical  calculations  allow  : 
10  sq.  ft.  of  pipe  for  one  ton  in  Open  Air  condensers. 

6  sq.  ft.  of  pipe  for  one  ton  in  Surface  condensers. 
14  sq.  ft.  of  pipe  for  one  ton  in  Submerged  condensers. 

Constructional  Details. 

Every  condenser  must  be  provided  with  a  back  pressure  or 
relief  valve,  which  acts  as  a  safety  valve  in  case  not  all  of  the 
steam  can  be  condensed  on  account  of  lack  of  condensing  water, 
or  for  any  other  reason. 

Fig.  A  illustrates  an  atmospheric  condenser,  a  number  of  inde- 
pendent coils  connected  to  two  headers.  Bach  coil  is  provided 


with   a    stop   valve    on    inlet  and    outlet,    and   a    live    steam    and 

purging   connection,    so   that  any   coil   can  be   cleaned   while   the 
balance  is  in  operation. 

For   large  plants   this    type  is   also    made   as    shown   in    Fig.    B, 


The  object  of  this  arrangement  is  the  division  of  the  area  of  the 
large  main  exhaust  pipe  into  the  many  small  areas  of  the  coils 
as  close  as  possible  to  the  main  inlet,  without  spacing  the  coils 
too  close,  which  would  prevent  the  cleaning  of  the  outside  sur- 
faces of  the  pipes. 

Where  a  very  hard  condensing  water  must  be  used  and  much 
cleaning  of  the  outside  surfaces  of  the  pipes  is  necessary, 
submerged  coils,  as  shown  in  Fig.  C,  have  been  used  successfully. 
The  area  of  the  main  exhaust  pipe  is  divided  into  two  branches, 
and  the  size  of  the  pipes  can  be  gradually  reduced  toward  the 
outlet  in  proportion  of  the  amount  of  steam  condensed  in  each 
pipe  while  passing  through  the  coil. 


74 


DISTILLING  APPARATUS. 


Submerged  condensers  can  be  well  drained  by  giving  all  the 
pipes  some  slope  toward  the  outlet. 

The  condenser  in  Fig.  D  is  similar  to  to  the  De  La  Vergne  am- 
monia condenser,  having  a  number  of  outlets  through  which  the 
water  of  condensation  is  drained  off. 


The  York  double  pipe  condenser  is  illustrated  in  Fig.  E.  Each 
section  consists  of  two  coils  which  are  connected  by  return  bends 
at  both  ends.  At  the  center  of  each  coil  is  a  vertical  header, 
one  of  which  is  for  the  steam  inlet  and  the  other  for  the  water 
outlet.  The  exhaust  steam  enters  the  header  on  top.  On  its  way 


D 


SL 
3X 
3L 


to  the  water  header  it  has  to  pass  but  one  return  bend,  all  of 
which  bends  have  a  slope  toward  the  water  header  for  a  perfect 
drainage. 

The   standard    atmospheric    condenser    of    the    York    Mfg.    Go.    is 
illustrated  in  Fig.  F.     These  coils  are  made  up  with  headers  which 


are  connected  with  straight  pipes.  The  steam  is  admitted  to  all 
pipes  at  the  same  time  and  has  not  to  pass  through  cramped 
passages  or  to  change  its  direction.  If  placed  horizontally,  the 
coils  could  be  used  in  a  submerged  condenser. 

The   Triumph  condenser,  Fig.   G,  uses  as  the  condensing  surface 
sheet  metal  instead  of  pipes,  in  the  form  of  V-shaped  boxes.     The 


DISTILLING  APPARATUS. 


75 


condensing  water  can  be  used  economically  and  the  flat  surfaces 
can  be  cleaned  very  easily  while  the  condenser  is  in  operation. 


For    special    purposes    and    local    condition    the    shell   condenser, 
Fig.   H,   is  used,   both  horizontally  and  vertically.      It  consists   of 


a  shell,  within  which  are  a  great  number  of  small  sized  seamless 
brass  or  copper  tubes,  through  which  the  condensing  water  passes, 
the  shell  being  filled  with  the  exhaust  steam. 


FIG.   26— A  to  H. 

This  type  is  very  efficient,  takes  little  space  and  can  be  placed 
anywhere  inside  the  building. 

DIMENSIONS  OF  SURFACE  CONDENSER  "H." 


Cooling 


too 
?00 

300 
400 
500 
600 
700 
$00 
IOOO 

I?QO 


lt>00 
I  A  00 
2000 


/ooo 
2000 
3000 
•Vono 
£000 

6000 
7OOO 
S(WO 
10  OOO 
13000 
MOOO 

,5oao 
'6000 
16000 
20000 


H    P 
•  t   2oll 


50 

100 

ZOO 

rso 

300 
350 
400 
SCO 
bOO 
7OO 
7SO 
600 
900 

IOOO 


82* 


4  10 


99 


/04 


22 


'£90 
2500 


4260 


5S90 
6390 
7060 
7450 
7920 
66oO 
9360 


DISTILLING  APPARATUS. 


Skimmer  and  Reboiler. 

During  the  condensation  of  the  exhaust  steam  more  or  less  air 
or  gas  is  absorbed  by  the  water.  The  reboiling  drives  the  im- 
purities to  the  surface  where  they  are  skimmed  off,  while  the  air 
and  gases  escape  through  a  vent  into  the  outer  atmosphere.  The 
water  should  enter  at  the  highest  possible  temperature  (about 
110°  to  112°)  so  as  to  economize  in  steam  for  reboiling. 

The  steam  coil  is  either  closed  or  open.  In  the  open  coil  the 
steam  pressure  is  reduced  to  a  few  pounds  and  the  condensation 
passes  through  the  perforations  and  mixes  with  the  water.  The 
closed  coil  needs  no  regulation  and  is  supplied  with  high  pressure 
steam.  The  condensation  is  either  carried  back  to  the  boiler 
by  gravity,  or  is  discharged  into  the  steam  condenser  by  a  steam 
trap. 

Mostly  used  are  the  cylindrical  tanks  and  the  rectangular  shal- 
low pans.  The  advantages  claimed  ior  the  former,  greater  body 
of  water,  large  skimming  line,  small  floor  space  and  simple  con- 
struction; for  the  latter,  large  surface  and  small  depth  of  boil- 
ing water,  which  are  said  to  better  assist  the  escape  of  the  air 
and  foul  gases,  constant  current  of  water  toward  skimmer,  pos- 
sible division  of  surface  into  parts  of  decreasing  ebullition. 

Leading  builders  use  from  two  to  four  square  feet  of  W.  I.  pipe 
surface  per  ton  of  ice  making  capacity  (less  for  brass  or  copper 
tubing). 

Constructional  Details. 

The  De  La  Vergne  Re- 
boiler,  A,  has  the  boiling 
tank  placed  centrally 
within  a  larger  tank,  the 
annular  space  between 
both  forming  the  skim- 
ming tank.  Being  placed 
at  the  same  level  with 
a  hot  water  storage 
tank,  the  water  level  is 
always  kept  full,  and  the 
ebullition  is  confined  to 
the  boil  tank,  leaving 
skimmer  in  a  state  of 
rest.  The  steam  coil  is 
closed  and  provided  with 
a  steam  trap. 

The  Triumph  Reboiler, 
B,  is  also  cylindrical, 
the  skimmer  being  a  V- 
shaped  annular  trough 
within  the  reboiler.  The 
steam  coil  is  open,  dis- 
charging the  condensa- 
tion near  the  surface  of 
the  water, 
used  by  Fred  W.  Wolf 


is 


Another  cylindrical  type,  Pig 
and  a  number  of  other  builders.  It  has  no  automatic  regulator. 
The  water  level  in  the  skimmer  and  the  boil  tank  is  kept  constant 
by  goose  neck  outlets. 

The  York  reboiler,  D,  is  of  the  rectangular  shape  with  open  steam 
coil.  The  oil  and  impurities  are  carried  by  the  water  current 
into  the  skimming  chamber,  where  they  are  skimmed  by  means 


DISTILLING  APPARATUS. 


77 


of  V-shaped   openings   in   the   end   of  tank   into   a   trough   at  the 
end  of  the  reboiler.     The  pure  water  is  discharged  from  the  bot- 
tom of  this  chamber. 
The    Frick    reboiler,    B,    is    divided    lengthwise    by    a    partition, 


SKIMMCK 


SKOUNO  PLMI. 


which   not   only    lengthens   the   travel   of    the   water,    but   brings 
same  in  a  counter-current  to  the  flow  of  steam  which  is  doubled 


£3e/i.  TANK 


r 


II 


DISTILLING  APPARATUS. 


by  this  division.  The  pipes  of  the  open  steam  coil  ire  not  per- 
forated, but  are  closed  with  caps,  each  of  which  ha*  ;<  small  hole 
for  the  discharge  of  condensation.  The  skimming  umi  discharge 
of  the  pure  water  are  similar  to  those  of  the  York  id-oiler. 

The  Wingrove  reboiler,  F,  is  a  combination  with  u  filter  for 
the  outgoing  pure  water.  The  steam  coil  is  open  and  pL"f orated 
at  the  end  of  the  pipes.  The  oil  and  floating  impuritic-s  are  car- 
ried into  the  skimming  chamber  over  a  special  shaped  plate  above 
the  filter. 

The   Bertsch   reboiler.    I,    is    a    combination    with    a    heater    in- 


serted  in  the  exhaust  line  in  front  of  the  condenser,  the  purpose 
of  which  is  to  deliver  the  condensed  water  to  the  reboiler  at 
the  temperature  of  the  exhaust  steam. 

The  condensed  water  from  the  condenser  passes  on  its  way 
to  the  reboiler  through  the  coil  of  the  heater.  The  condensation 
from  the  heater  can  be  drained  into  the  reboiler  or  float  tank. 

In  connection  with  a  condensing  engine  and  a  vacuum  steam 
condenser,  a  vacuum  reboiler  saves  steam,  because  the  boiling 
point  is  much  lower,  and  it  saves  cooling  water,  because  the 
boiling  temperature  corresponding  to  the  vacuum  is  not  above 
140°  F. 

In   the   De  La   Vergne  vacuum  reboiler,   G,   the  water  from   the 


DISTILLING  APPARATUS. 


79 


vacuum  steam  condenser  enters  the  reboiler  by  gravity  near  the 
bottom,  and  is  removed  and  delivered  to  the  hot  water  storage 
tank  by  a  pump  which  is  regulated  by  a  float  within  the  re- 
boiler,  raised  or  lowered  by  the  variation  of  the  water  level. 
The  air  and  gases  are  drawn  into  the  steam  condenser  and  re- 
moved by  the  air  pump  creating  the  vacuum.  The  closed  steam 
coil  discharges  *be  condensation  into  a  pot,  from  which  it  is 
siphoned  into  th^  reboiler  through  the  water  inlet  line  whenever 
the  float  within  the  pot  opens  the  valve. 

The  York  vacuum  reboiler,  H,  contains  within  an  air  tight 
shell  a  series  of  shallow  pans,  each  of  which  has  'an  overflow 
and  a  dam  to  maintain  a  certain  depth  of  water.  The  water 


n  PUMP 
FIG.   27— A   to   H. 


drops  from  one  pan  to  the  other  and  circulates  through  each  pan. 
The  top-most  pan  is  provided  with  a  closed  steam  coil  for  boiling. 
At  the  bottom  of  the  shell  is  a  float  tank  for  the  accumulation  of 
the  pure  water  which  is  removed  by  a  pump.  The  float  in  the 
float  tank  regulates  the  steam  for  the  water  pump,  which  forces 
the  pure  water  through  the  cooler  and  filters.  At  the  top  of 
the  shell  is  the  air  outlet,  which  is  either  direct  connected  to  an 
air  pump,  or  to  a  vacuum  steam  condenser. 

Frick  Reboiler,  IS  in.  high,  30  in.  wide. 
Length  :  1  to     6  ton  plants =3  ft.  6  in. 
8  to  12     "         "      =7  ft. 

15     "        "      —10  ft.  6  in. 

25     "         "      =  13  ft.   9  in. 

50     "         "      =20  ft.  6  in. 

100     "        "      =23  ft.  9  in. 

De  La  Vergne  Reboiler. 

2  to  15  ton  plants  =  3  ft.  dia.,  4  ft.  high. 
20  to  30     "        "      =3  ft.  6  in.  dia.,  4  ft.  8%  in.  high. 
40  to  60     "        "     —.4  ft.  dia.,  5  ft.  high. 

Frick  Steam  Condenser,  8  pipes  high. 

5  ton  plant=l  coil,  15  ft.  long. 

10     "       "     =2  coils,  15  ft.  long. 

20     "       "      =4  colls,  15  ft.  long. 

50     "       "      =9  coils,   15  ft.  long. 

100     "       "     =17  coils,  15  ft.  long. 


8o 


DISTILLING  APPARATUS. 


Water  Regulator. 

The  flow  of  the  water  leaving  the  reboiler  must  be  automatically 
regulated  before  entering  the  cooler.  The  principle  of  such 
regulators  is  the  automatic  opening  and  closing  of  a  valve  (butter- 
fly or  quick  opening)  in  the  distilled  water  line. 

A  good  regulator  must  allow  a  great  variation  in  the  quantity 
of  water  passing  at  each  operation,  as  well  as  in  the  number  of 
operations. 


tor,  A,  consists  of  an  open 
cylinder  with  a  float  and  Is 
operated  by  the  waste  water 
of  the  steam  condenser.  It 
can  be  placed  anywhere  near 
the  distilled  water  supply 
pipe. 

The  operation  Is  as  follows: 
As  long  as  the  water  lerel 
In  the  hot  water  storage  tank 
is  at  normal  height  the  but- 
terfly valve  in  the  waste 
water  line  is  open  and  admits 
water  to  the  regulator,  there- 
by raising  the  float  whicli 
opens  the  butterfly  valve  in 
the  pure  water  line  and  al- 
lows the  water  to  pass  to  the 
freezing  tank.  When  the 
water  In  the  hot  water  stor- 
age tank  is  low,  both  butter 


fly  valves  close  and  stay  closed  until  the  pure  water  in  the  storage 
tank  reaches  again  the  normal  height,  when  the  same  operation  is 
repeated. 

The  York  regulator,  B,  consists  of  a  cylinder  with  a  plunger  to 
which  two  valves  are  attached,  one  for  the  pure  water  and  one  for 
the  waste  water.  The  water  from  the  skimmer  is  used  for  operat- 
ing the  regulators,  and  the  operation  is  as  follows  : 

Whenever  the  reboiler  is 
skimming,  the  mixture  of 
oil  and  water  fills  the  pipe 
connecting  the  skimmer 
with  the  regulator.  As 
soon  as  the  water  column 
in  this  pipe  is  of  sufficient 
height,  the  pressure  so 
created  elevates  the  plun- 
ger, whereby  both  valves 
are  opened.  The  pure 
water  then  passes  from  the 
filter  to  the  storage  tank, 
and  the  skimming  water 
drains  through  the  waste 
pipe.  The  skimming  in 
the  reboiler  stops  and  the 
water  in  the  regulator  and 
its  supply  pipe  drains  out, 
causing  the  plunger  to 
lower  and  both  valves  to 
close,  until  the  reboiler 
skims  again.  For  the  re- 
lief of  the  air  which  might 
get  Into  the  cylinder,  a 


DISTILLING  APPARATUS. 


81 


vent  Is  provided,  which, 
opens  when  the  plunger 
Is  in  its  highest  position. 
By  the  use  of  the  skim- 
ming water  the  plunger  is 
always  well  lubricated. 

The  Wingrove  regulator, 
C,  differs  from  the  York 
regulator  only  in  the  me- 
chanical means,  and  the 
principle  is  exactly  the 
same  in  both  and  covered 
by  the  same  description. 

The  FricTc  regulator,  D, 
consists  of  two  principal 
parts,  the  receiving  tank 
and  the  counterbalanced 
bucket  which  operates  the 
pure  water  valve.  When 
the  water  in  the  reboiler 
reaches  the  overflow  tube 

by  which  the  skimming  is  regulated,  the  receiving  tank  begins  to 
fill  to  the  top  of  the  siphon,  after  which  the  water  passes  through 
the  siphon  to  the  bucket. 

As  soon  as  the  weight  of  the  water  overcomes  the  balance  weight, 
the  bucket  lowers  and  the  pure  water  valve  opens,  allowing  the 
pure  water  to  pass  to  the  storage  tank.  After  the  bucket  is  filled 
to  the  top  of  its  own  siphon,  it  begins  to  empty  its  contents  into 
the  float  tank  from  which  the  water  is  pumped  back  to  the  reboiler. 
When  the  water  in  the  reboiler  is  lowered  below  the  top  of  the 
overflow  tube,  the  supply  to  the  receiving  tank  and1  the  bucket 
stops,  and  the  bucket  is  siphoned  empty  and  becomes  lighter  than 
the  balance  weight,  which  raises  the  bucket  and  closes  the  pure 
water  valve. 

Bertsoh's  regulator,  E,  is  a  combination  of  the  float  and  siphon 
types.  The  water  pressure  against  the  valve  seat  is  counterbal- 
anced by  an  adjustable  weight.  As  soon  as  the  reboiler  is  skimming, 

the  float  tank  fills,  the  float 
rises  and  relieves  the  valve, 
allowing  the  water  to  pass  to 
the  storage  or  freezing  tank. 
When  the  float  reaches  a  cer- 
tain height,  the  lever  opens 
the  drain  pipe  and  starts  the 
siphon  which  empties  the 
float  tank  in  the  desired  time, 
and  this  is  regulated  by  the 
drain  valve. 

Condensed  Water  Cooler. 

Its  purpose  is  to  cool  the 
boiling  hot  water,  as  it  comes 
from  the  rehoiler,  as  nearly  as 
possible  to  the  temperature  of 
the  cooling  water,  after  which 
any  further  cooling  must  be 
done  by  mechanical  refrigera- 
tion. 

Each  cooling  coil  should  be 
provided  with  a  drain  or 
washout  connection  at  the 
bottom,  and  a  steam  connec- 
tion at  the  top,  as  during  the 


82 


DISTILLING  APPARATUS. 


cooling  of  the  water  ,some  of 
the  oil  contained  therein  Is 
separated  and  forms  a  coating 
on  the  inside  surface  of  the 
pipes,  which  can  only  be  re- 
moved by  a  blow  of  live  steam. 
The  cooler  is  of  the  double 
pipe  and1  more  commonly  of 
the  atmospheric  type.  Its  con- 
struction is  sufficiently  illus- 
trated in  the  various  arrange- 
ments of  the  different  builders 
below. 
Filter. 

The  cooled  water  receives  a 
final  filtration,  in  order  to  free 
it  from  any  odors  and  foreign 
matters  still  contained  there- 
in. The  most  common  place 
for  the  filters  is  after  the 
cooling  coils,  and,  again,  right 
FIG.  28.  A  TO  E.  before  the  can  filler.  As  the 

filtering  media  are  mostly  used1  sand,  crushed  quartz,  maple  char- 
coal, bone  black  (animal  charcoal),  pulp  and  felt  or  cotton  cloth. 

All  of  these  materials  have  a  purely  mechanical  action  upon 
the  water,  with  the  exception  of  the  wood  and  animal  charcoal, 
which  combine  with  the  mechanical  action  also  a  chemical  one, 
inasmuch  as  they  have  power  to  absorb  any  kind  of  odor.  The 
charcoal  filters  are  therefore  also  called  "deodorizers." 

The  method  of  filtering  differs.  Some  filter  from  bottom  to 
top,  for  which  method  It  is  claimed  that  the  heavy  particles  in 
the  water  tend  to  fall  to  the  bottom  instead  of  clogging  the  fil- 
tering material.  Others  filter  from  top  to  bottom  and  the  claim 
is  that  the  oily  substance  contained  in  the  water  remains  floating 
on  top  instead  of  being  forced  down  through  the  filtering  ma- 
terial. To  cleanse  these  filters,  the  flow  of  the  water  is  reversed 
in  order  to  loosen  the  packet  material  and  to  wash  the  same. 
Where  steam  is  used  for  cleansing,  the  content  of  the  filter  is 
first  blown  with  live  steam,  and  afterwards  washed  in  the  way 
as  before  stated. 

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DISTILLING  APPARATUS. 

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Storage  Tank. 

The  storage  tank  serves  for  the  purpose  of  storing  up  a  large 
amount  of  distilled  water.  A  wooden  float  generally  covers  the 
whole  area  of  the  water  to  prevent  any  reabsorption  of  air. 

Many  builders  use  the  storage  also  as  a  fore  cooler,  having 
ammonia  coils  in  the  inside.  The  tanks  are  made  either  cylin- 
drical or  rectangular,  of  wood  or  of  iron,  and  the  cooling  pipes 
are  either  an  independent  coil  or  simply  an  expansion  of  the 
ammonia  suction  pipe.  The  latter  method  is  used  in  all  plants 
where  the  machine  can  not  work  with  backfrost,  and  the  storage 
tank  is  used  as  much  for  preventing  back-frost  as  for  cooling  the 
distilled  water.  The  temperature  of  the  water  can  be  regulated 
at  will  where  an  independent  coil  is  used  for  cooling.  Where  the 
return  from  the  freezing  tank  is  used  for  cooling,  the  temperature 
of  the  water  depends  entirely  on  the  amount  of  heat  the  returning 
vapor  can  take  up,  which  in  many  cases  is  very  little. 

Bach  can  is  filled  separately  by  means  of  hose  and  can  filler, 
which  delivers  the  water  to  the  bottom  of  the  can,  so  that  the 
water  does  not  absorb  more  air  as  it  rushes  in. 

DIMENSIONS  OF    CYLINDRICAL  TANKS    (NO    OOILS). 

Tons  ice.  Dia.  Height. 

5  2V2ift.  31/2  ft. 

10  3      ft.  4      ft. 

20  3V2  ft.  5      ft. 

40  4      ft.  Q      ft. 


DIMENSIONS  OF  SQUARE  TANKS    (EXP.   OOILS). 


Tons 

ice. 

10 

20 

30 

40 

50 

75 

100 

200 


Length. 

10  ft. 

11  ft. 

12  ft. 
12      ft. 
14y2  ft. 
25      ft. 
17     ft. 
24     ft. 


Width. 

2y2  ft. 

31/2   ft. 

4y2  ft. 
41/2  ft. 
41/2  ft. 
4y2  ft. 
7y2  ft. 
91/2  ft. 


Height. 

sy2  ft. 

4      ft. 

4y2  ft. 
sy2  ft. 
5%  ft. 
5y2  ft. 

sy2  ft. 


2  in. 

Pipe. 

58ft. 

145  ft. 

218  ft. 

290ft. 

363  ft. 

544  ft. 

725  ft. 

1,450  ft. 


Size  of 

water  pipe. 

1      in. 

1  in. 
1%  in. 
1%  in. 
1%  ft. 

2  In. 
2^  in. 

3  ft. 


84 


DISTILLING  APPARATUS. 


86 


DISTILLING  APPARATUS. 


DISTILLING  APPARATUS. 


The  Evaporator  System. 

The  economy  of  ice  production  depends  upon  the  efficiency  of 
the  boiler.  If  the  boiler  evaporates  8  Ibs.  of  water  per  pound  of 
coal  and  we  lose  25  per  cent,  by  steam  cylinder  condensation, 
condensation  in  exhaust  pipe  and  loss  by  reboiling  and  skimming, 
we  may  produce  6  tons  of  ice  per  ton  of  coal. 

Efforts  were  made  to  improve  the  economy  and  the  use  of  com- 
pound condensing  engines  in  connection  with  an  evaporator  in 
which  the  exhaust  steam  is  used  to  produce  additional  distilled 
water  was  resorted  to. 

In  all  ice  making  plants  with  evaporators  now  in  operation,  the 
Lillie  evaporator  has  been  used.  It  consists  of  a  cast-iron  shell 
and  is  provided  with  copper  tubes.  Near  one  end  is  the  tube 
head  which  divides  the  evaporator  into  two  parts,  the  steam 
space  and  the  vapor  space.  One  end  of  the  copper  tubes  is  ex 
panded  in  the  tube  head,  the  other  end  is  closed,  but  the  closed 


FIG.  32.     DIAGRAM  OF  EVAPORATOR  SYSTEM. 

ends  are  each  provided  with  a  very  small  air  vent  hole.  Under 
the  evaporator  a  centrifugal  pump  is  placed  which  serves  to  cir- 
culate the  water  over  the  tubes,  a  float  in  the  float  box  keeps 
the  water  at  a  pre-determined  level. 

The  exhaust  steam  from  the  low  pressure  cylinder,  usually 
under  a  vacuum  of  18"  and  a  temperature  of  169°  Fahr.,  enters 
the  steam  space  of  the  evaporator  and  thence  the  copper  tubes, 
the  water  which  is  showered  over  the  tubes  evaporates  owing  to 
the  lower  vacuum,  25"  or  26",  which,  by  means  of  the  condenser 
and  air  pump  is  maintained  in  this  space.  The  temperature  of 
vapor  under  a  vacuum  of  26"  is  126°,  and  the  difference  between 
126°  and  169°  is  quite  sufficient  to  produce  boiling  and  consequently 
evaporation.  The  steam  which  enters  the  copper  tubes  is  con- 
densed, drops  to  the  bottom  of  the  steam  space  and  from  there  is 
periodically  discharged  into  the  steam  condenser. 

The  vapor  is,  of  course,  pure,  clean  and  free  from  any  odor 
owing  to  the  fact  that  it  is  distilled  at  a  low  temperature ;  the 
steam,  however,  which  has  done  its  work  in  both  the  high  and 
low  pressure  cylinders  of  the  engine,  contains  all  the  impurities 
which  such  steam  is  subject  to  in  any  ice  plant,  viz.,  oil,  oxide 
of  iron  and  free  ammonia.  In  order  to  free  it  from  the  oil  and 
oxide  of  iron  it  must  be  washed  or  passed  through  a  coke  scrubber 
in  the  usual  way  except  that  in  this  case  the  oil  extractor  or  coke 


88  DISTILLING  APPARATUS. 

scrubber  must  be  operated  under  the  same  vacuum  which  is  main- 
tained in  the  steam  space  of  the  evaporator. 

The  vapor  after  it  leaves  the  evaporator  enters  the  top  of  the 
steam  condenser,  the  air  pump  by  taking  away  the  air  and  most 
of  the  ammoniacal  gases  which  have  not  yet  been  re-absorbed  by 
the  distilled  water  maintains  a  vacuum  of  from  25  to  2t>". 

The  condensed  steam  leaves  at  the  bottom  of  tlie  condenser  and 
flows  over  to  the  reboiler,  whose  vacuum  is  maintained  through  a 
by-pass  with  the  vacuum  part  of  the  steam  condenser.  It  enters 
the  reboiler  under  a  vacuum  of  26"  and  a  temperature  of 
120°  and  needs  only  to  be  heated  to  126°  in  order  to  boil. 

When  the  water  level  witirtn  has  risen  to  a  certain  height, 
a  float  inside  will  act  upon  the  steam  valve  of  the  pump,  which 
will  commence  to  pump  the  water  away  up  to  the  storage  tank 
on  the  next  floor,  from  which  it  passes  through  the  usual  course 
of  cooling  and  filtering  before  entering  the  cans. 

With  the  Lillie  evaporator  seven-eighths  of  a  pound  of 
vapor  can  be  produced  for  every  pound  of  steam.  To  produce 
100  tons  of  distilled  water  would  required  fifty-five  tons  of  ex- 
haust steam,  but  in  order  to  have  that  quantity  enter  the  evap- 
orator seventy-three  or  seventy-four  tons  must  have  entered  the 
high  pressure  steam  cylinder  and  this  determines  the  economy  of 
the  plant. 

In  practice,  10  to  11  tons  of  distilled  water  can  ice  can  be  made 
per  ton  of  coal  if  the  latter  evaporates  eight  tons  of  water  under 
the  working  pressure  in  the  boiler  per  ton  of  coal. 

The  exhaust  steam  from  auxiliary  machinery  and  pumps  is  used 
for  heating  the  boiler  feed  water,  and  the  water  for  the  evap- 
orator, if  it  is  suitable,  is  heated  by  using  it  for  cooling  the 
distilled  water. 

The  operation  of  such  a  plant  is  extremely  simple,  and  it  is 
not  difficult  for  the  operating  engineer  to  understand  it,  in  fact  it 
requires  no  more  attention  than  an  ice  plant  with  compressors 
driven  by  compound  condensing  steam  engine.  (L.  Block,  Trans. 
A.  S.  R.  E.  19U6,  Abridged.) 

Multiple  Effect  Evaporators. 

Very  large  plants  are  enabled  to  use  highly  economical  engines 
by  having  a  double  or  triple  effect  evaporator.  In  this  way  the 
exhaust  steam  may  be  able  to  produce  almost  3  times  as  much  dis- 
tilled water  as  exhaust  steam  is  condensed,  as  we  will  see  from  the 
following  calculation: 

Assumed  steam   consumption  =  2,000  Ibs.  per  hour. 
Distilled      water      required  =  4,500  Ibs.  per  hour. 
The  exhaust  steam  enters  the  first  evaporator  under  a  back  pres- 
sure of  5  Ibs.   above  the  atmosphere.     The  last  evaporator  is   In 
connection  with   a  surface  condenser   with   air  pump,   and  a  high 
vacuum  is  maintained  in   its  vapor  end.     A  moderate  vacuum  is 
maintained  in  No.  II  and  a  low  vacuum  in  No.  I. 

Let  us  assume   that   the  supply  of  water    (which   may  be   used 
first  in  the  steam  condenser)  enters  No.  I  at  a  temperature  of  120°. 
1.    The  first  operation  will  be  to   raise  the  4,500  Ibs.   of  water 
from  120°  to  203°  F.  (temp,  of  vaporization  in  No.  I). 
4,500  (203  —  120)   =  373,500  units,  which  requires  an  equivalent 
373,500 

of =  3SO  Ibs.  steam,  condensed.  (952  =  lat.  heat  at  6  Ibs. 

952 

G.  Press.)  Deducting  this  from  2,000  Ibs.  initial  steam,  leaves 
1,610  Ibs.  of  steam,  the  condensation  of  which  will  cause  a  certain 
amount  of  water  being  evaporated;  952  being  the  latent  heat  of 
the  steam  in  No.  I,  and  972  that  of  the  water  at  203°,  the  amount 


DISTILLING  APPARATUS. 


of  vapor  formed  by  the  condensation  of  1,610  Ibs.  of  steam  will  be 
1610  X  952 

. =  1,580  Ibs.  of  vapor  passing  to  No.  II.     Deducting 

972 

this  weight  from  the  total  of  4,500  Ibs.    =   4,500  —  1,580  =  2,920 
Ibs.  of  water  passing  to  No.  II. 

2.  This  water  enters  at  203°.  But  as  the  temperature  in  No. 
II,  due  to  the  better  vacuum  is  only  181",  it  will,  in  falling 
203  —  181  =  22°,  give  off  vapor  as  follows: 


FIG.    33.     TRIPLE    EFFECT    EVAPORATOR. 


2920  X  22 


=  63  Ibs.  of  vapor. 


992  (lat.  heat) 

As  the  1,580  Ibs.  of  vapor  from  No.  I  are  condensed  in  No.  II, 
it  will  under  the  better  vacuum  and  lower  temperature  evaporate 
nearly  the  same  weight  of  water.  Adding  1,580  to  63  gives  a 
total  =  1,643  Ibs.  of  vapor  passing  to  No.  III.  Deducting  this 
weight  from  2,920  =  1,643  —  2,920  =1,277  Ibs.  of  water  passing 
to  No.  III. 

3.  Evaporator  No.  Ill  has  a  vacuum  of  24"  and  a  corresponding 
temperature  of  145°. 

The  water  in  falling  181  —  145  =  36°,  will  give  off  vapor  as 
follows:  1277  X  36 

=  45  Ibs.  of  vapor. 

1012  (lat.  heat) 

As  in  No.  II,  taking  the  evaporation  in  No.  Ill  equal  in  weight 
to  the  condensation,  or  1,643  Ibs.,  the  total  will  be  1,643  +  45 
=  1,688  Ibs. 

This  is  far  in  excess  of  what  is  actually  left  to  evaporate, 
namely,  1,277  Ibs.  It  shows  that  the  capacity  of  the  triple  effect 
is  too  great,  or  in  other  words,  that  less  steam  was  needed  to 
evaporate  the  initial  amount  of  water. 

The  sum  of  the  different  weights  of  vapor  passing  out  of  the 
three  vessels  to  be  condensed  for  the  supply  of  the  ice  cans  is: 

1,580  +  1,643  +  1,277  =  4,500  Ibs. 

By  calculations  we  find  out  that  only  about  1,860  Ibs.  of  exhaust 
steam  are  required  to  distill  that  amount  of  water  from  an  initial 
temperature  of  120°. 

4,500 
This  gives  a  ratio  of  - 

1,860 
=  2.42  Ibs.  of  distilled  water  for  each  Ib.  of  exhaust  steam. 


SPACE  FOR  CAN  ICE  PLANTS. 


If  the  water  is  heated  up  to  200°  before  entering  No.  I,  the 
ratio  will  be  about  3  Ibs.  of  water  per  Ib.  of  steam. 

The  condensed  steam,  not  being  required  for  ice  maMng,  ivill 
60  returned  to  the  boiler  as  boiler  feed  water. 

The  vapor  pipes  are  increased  in  size  so  as  to  make  the  fall  of 
the  temperature  between  the  vessels  as  slight  as  possible. 
Space  Required  for  Can  Ice  Plants. 

The  illustrations  below  give  an  approximate  idea  of  the  space 
required  for  a  given  size  plant.  Of  course,  these  dimensions  can 
be  varied  greatly  to  suit  local  conditions. 


T~T 


FIG.   34.  HORIZONTAL  D.   A.  MACHINE    (WOLF). 

Capacity  tons  . .  5      10      15      20      25      30      40      50      60  80  100 

A  in   ft 30      35      37      40      42      42      49      49      54  59  73 

B  in  ft 56      73      78      85      95    107    120    135    150  154  160 


FIG.   35.     VERTICAL  S.  A.  MACHINE   (YORK). 

Capacity  tons  . .     6      10      15      20      25      30      40      50      60  75  100 

A   in   ft 40      44      47      50      53      56      60      64      69  72  70 

B   in  ft 53      64      75      87      97    108    121    135    150  163  174 


SPACE  FOR  CAN  ICE  PLANTS. 


Through  the  courtesy  of  the  Frick  Co.  we  are  enabled  to  show 
in  the  following  pages  complete  lay-outs  of  ice  plants  ranging 
from  a  daily  capacity  of  6  tons  to  60  tons. 


J.   $ 


92 


SPACE  FOR  CAN  ICE  PLANTS. 


| ML 


i     i  :  '.i  Hllilll  t 

" 


--^1-0-- 


1 


FIG.  ST. 


SPACE  FOR  CAN  ICE  PLANTS. 


93 


01 

-H 
O 


o 

-H 
O 


SPACE  FOR  CAN  ICE  PLANTS. 


FIG.  41. 


t-8-2^ 

*  

I          7-> 
'--rf 

-c 

t  | 

BOILERS                             ,ia 

1, 

,  wooa 
ONmnsia 

1 

r 
"> 

JIIIH  f    = 

*-§  —  33i5^-—rl 
2     J^  JJ 

SPACE  FOR  CAN  ICE  PLANTS. 


FIG.    43. 


Plate  Ice  Plants 

Plato  ice  having  its  growth  in  thickness  from  one  side  only, 
the  formation  of  ice  proceeds  from  the  freezing  plate  outward, 
and  certain  undesirable  properties  of  the  water  held  in  solution 
or  mechanically  suspended  or  other  than  chemically  fixed,  are 
separated  and  rejected  by  the  slowly  freezing  water.  The  residual 
or  unfrozen  water,  at  the  termination  of  the  freezing  period,  is 
drained  off,  the  tanks  then  being  refilled  with  fresh  water. 


V///A 

FIG.  44.     DIRECT  EXPANSION  PLATE  PLANT. 


IOO 


PLATE  ICE  PLANTS. 


Plate  ice  is  made  by  the  following  methods  :  The  direct  expan- 
sion plate;  the  direct  expansion  plate,  icith  still  'brine,  known  as 
the  "Smith"  plate;  the  brine  cell  plate;  the  brine  coil  plate,  and 
the  block  system  with  either  direct  expansion  or  brine  coils. 

The  direct  expansion  plate  is  the  simplest  in  construction  and 
consists  of  direct  expansion  zigzag  coils  with  %-inch  plates  of 
iron  bolted  or  riveted  in  place.  The  thawing  off  of  the  face  of 
ice  is  accomplished  by  turning  the  hot  ammonia  gas  from  the 
machine  direct  into  the  tank  coils. 

The  direct  expansion  plate  u'ith  still  brine,  known  as  the 
"Smith"  plate,  is  similar  in  construction,  excepting  that  the  coil 
Is  immersed  in  a  brine  solution  contained  in  a  water  and  brine 
tight  cell.  Thawing  off  is  accomplished  by  turning  hot  gas  into 
the  coils. 

The  brine  cell  plate  consists  of  a  tightly  caulked  and  riveted 
cell  or  tank  about  four  inches  thick,  provided  with  proper  bulk- 
heads or  distributing  pipes,  to  give  an  even  distribution  of  brine 
throughout  the  plate.  The  thawing  off  of  the  face  of  the  ice  is 
accomplished  by  circulating  warm  brine  through  the  plate. 

The  brine  coil  plate  is  similar  to  the  direct  expansion  plate, 
excepting  that  brine  is  circulated  through  the  coil  instead  of 
ammonia.  Thawing  off  is  accomplished  by  means  of  warm  brine 
circulated  through  the  coils. 


FIG.    45.     BRINE    COIL    PLATE    PLANT. 

In  the  block  system  the  ice  is  formed  directly  on  the  coils, 
through  which  either  ammonia  or  brine  is  circulated.  After  tem- 
pering, the  ice  is  cut  off  in  blocks  the  full  depth  of  the  plate 
by  means  of  steam  cutters,  which  are  guided  through  the  ice 
close  to  the  coils. 

The  method  of  harvesting  is  similar  in  all  of  the  foregoing  sys- 
tems, excepting  that  in  use  for  harvesting  block  ice.  Some  use 
hollow  lifting  rods  and  thaw  them  out  with  steam;  others  use 
solid  rods  and  cut  them  out  when  cutting  up  the  ice;  and  others 
again  use  chains  which  are  slipped  around  the  cake  when  it  floats 
up  in  the  tank. 

Cutting  up  the  plate  is  accomplished  by  means  of  steam  cut- 
ters, power  saws  and  hand  plows.  In  the  block  system,  however, 
where  the  ice  is  cut  off  the  plate  in  the  tank,  it  only  remains 
to  remove  the  cakes  by  means  of  a  light  crane  and  hoist  and 
divide  them  into  the  required  sizes  with  an  axe  or  bar. 


101 


Agitation  is  accomplished  by  means  of  air  jets  located  midway 
between  the  plates,  sometimes  in  the  center,  sometimes  three  or 
four  feet  from  one  end  and  sometimes  at  both  ends  of  the  plates. 

In  well  designed  plants  the  production  of  a  square  top  has  been 
fairly  well  solved  and  it  only  remains  for  the  owner  to  see  to  it 
that  a  constant  water  level  is  maintained  in  the  tank  while  the 
ice  is  in  process  of  formation. 

From  an  economic  standpoint,  it  is  immaterial  whether  the  ice 
as  harvested  from  the  tank  has  round  or  square  ends,  unless  the 
tank  be  so  designed  that  no  ice  is  formed  between  thaw  pipes  or 
in  back  of  tha\^  planks.  This  is  especially  true  if  the  scrap  ice 
can  be  utilized. 

A  thawing  system  has  been  designed  requiring  for  its  proper 
operation  iron  freezing  tanks.  The  ice  is  formed  up  to  the  bottom 
and  sides  of  the  tank  and  on  the  outside  of  the  tank  around  each 
cell  consisting  of  two  plates  of  ice,  a  hollow  space  is  formed  by 
means  of  studding  and  sheathing.  In  this  space  are  steam  coils 
which  heat  the  outside  of  the  iron  tank  and  thus  loosen  the  ice 
from  the  bottom  and  ends. 

American  Linde  Plate  System. — The  freezing  plates  are  con- 
structed of  square  pipes,  which,  lying  closely  together,  make  a 
perfect  sheet.  They  consist  of  two  zig-zag  coils,  which  interlock- 
in  each  other.  Through  one  of  these  coils  (having  the  larger 
area)  cold  ammonia  vapors  are  passed  and  through  the  smaller 
one  brine  is  passed. 

The  working  of  these  freezing  plates  is  as  follows: 

When  the  cold  ammonia  vapors  are  passed  through  the  ammonia 
coil,  the  cold  is  evenly  transmitted  through  the  whole  surface  of 
the  pipes,  and  the  brine  coil,  which  is  surrounded  on  two  sides  by 
the  cold  ammonia  coil,  will  have  nearly  the  same  temperature  as 
the  ammonia  coil,  so  that  the  freezing  along  the  whole  plate  will 
take  place  just  as  fast  as  if  the  plate  consisted  entirely  of  one 
ammonia  coil.  When  we  want  to  loosen  the  plate  of  ice  from 


FIG.    46.     AMERICAN    LINDB    PLATE    SYSTEM. 


the  freezing  plate,  shut  off  the  supply  of  liquid  ammonia  and 
open  the  valve  which  allows  warm  brine  to  pass  through  the 
brine  coil. 

After  the  plate  is  loosened,  close  the  brine  valve  and  open  the 
valve  which  lets  the  liquid  ammonia  pass  through  the  ammonia  coil. 
To  get  the  ice  plates  square  the  brine  pipes  are  covered  with 
sheet  iron.  The  plate  of  ice  forms  inside  this  sheet  and  when  it 
has  formd  thick  enough  and  needs  to  be  loosened,  the  same  valve 


102  PLATE  ICE  PLANTS. 

which  lets  warm  brine  pass  through  the  brine  coil  interlocked 
with  the  freezing  coil  also  lets  brine  pass  through  these  coils, 
so  that  the  ice  is  loosened  from  the  plate. 

An  absorption  machine  under  the  right  conditions  should  produce 
up  to  12  tons  of  ice  per  ton  of  coal  burned. 

This  figure  includes  all  of  the  coal  burned  to  provide  steam  for 
the  water  pump,  ammonia  pump,  condensed  steam  pump,  agitating 
apparatus,  crane  operation  and  so  forth.  Actual  results  on  a  sea- 
son's business  show  10  tons  of  ice  sold  per  ton  of  coal  bought. 

Another  advantage  of  such  a  plant  is  that  cheap  coal  can  be 
burned,  providing  a  proper  boiler  plant  has  been  installed. 

The  following  costs  per  ton  for  operating  a  50-ton  plant  may 
be  interesting: 

Coal  at  $2.20  per  ton $0.22 

Labor 34 

Ammonia    06 

Incidentals  and  repairs 24 

Interest  on  investment 25 

Taxes  and  insurance .11 


Total  to  produce  1  ton  of  ice $1.26 

The  factory  cost  of  the  ice  is  86  cents  per  ton,  including  repairs. 
A  compression  machine  wth  compound  condensing  engine  and 
with  all  pumps,  etc.,  driven  by  the  compressor  engine  would  re- 
quire at  least  130  H.  P.  for  a  50-ton  ice-making  plant  and  with 
an  evaporation  of  7-1  in  the  boiler  plant,  it  would  require  the 
burning  of  4%  tons  of  coal  per  day  which  would  be  equivalent 
to  the  making  of  11  tons  of  ice  per  ton  of  coal  burned.  It  Is 
safe  to  say  that  not  over  ten  tons  of  ice  per  ton  of  coal  burned 
would  be  sold.  So  that  from  the  standpoint  of  coal  economy  the 
tico  plants  would  be  practically  equal. 

The  cost  per  ton  for  operating  a  50-ton  compression  plant  would 
be  about  as  follows: 

Coal  at  $3.20  per  ton $0.32 

Labor   34 

Ammonia 03 

Incidentals  and   repairs 18 

Interest  on   the   investment 25 

Taxes  and  insurance 11 


Total  to  produce  1  ton  of  ice $1.23 

In  this  case  the  factory  cost  of  the  ice  is  87  cents,  including 
repairs. 

The  difference  in  factory  cost  per  ton  is  so  small  that  the  whole 
matter  resolves  itself  into  the  question  as  to  which  type  of  machine 
is  best  adapted  to  the  particular  conditions  existing  in  the  im- 
mediate vicinity  in  which  the  plant  is  to  be  erected. 

A  stll  greater  economy  in  the  production  of  plate  ice  may  be 
attained  by  a  combination  of  the  absorption  and  compression 
machines.  The  steam  consumption  of  both  typos  of  machines  is 
a  well  known  quantity.  If,  then,  the  combination  plant  be  so 
proportioned  that  all  of  the  steam  required  to  operate  a  simple 
Corliss  engine  be  utilized  in  an  absorption  machine  at,  say,  ten 
pounds  pressure,  either  the  absorption  machine  or  the  compres- 
sion machine  will  be  operated  at  no  cost  for  coal. 

Assume  that  a  100-ton  plate  plant  be  so  designed.  Then  a  30- 
ton  compression  ice-making  machine  will  drive  a  70-ton  absorp- 
tion ice-making  machine  with  its  exhaust  steam  after  the  steam 
has  done  its  work  in  the  compressor  engine.  A  plant  designed  on 


PLATE  ICE  PLANTS.  103 

these  lines  would  turn  out  14  tons  of  ice  per  ton  of  coal  burned 
and  the  cost  per  ton  for  operation  would  be  about  as  follows: 

Coal  at  $2.20  per  ton $0.16 

Labor 30 

Ammonia  05 

Incidentals  and  repairs 21 

Interest  on  investment 25 

Taxes  and  insurance 11 


Total  to  produce  1  ton  of  ice $1.08 

The  factory  cost  per  ton  of  ice  is  in  this  instance  reduced  to  72 
cents  and  the  difference  in  the  cost  of  production  in  favor  of 
the  combined  plant  is  15  cents  per  ton,  which  on  a  yearly  output 
of  20,000  tons,  gives  the  substantial  sum  of  $3,000  per  annum 
saved.  (K.  Wegeman,  Trans.  West.  Ice  Ass'n.  1907.  Abridged.) 

About  250  square  feet  of  freezing  surface  will  be  required  per 
ton  per  24  hours  on  a  brine  plant  and  in  a  direct  expansion  plant 
about  275.  The  brine  plants  are  more  easy  to  operate  than  the 
direct  expansion  plants,  for  the  reason  that  the  plant  can  he 
operated  more  continuously  under  the  same  conditions.  That 
is,  the  condition  does  not  fluctuate  so  easily,  and  the  ice  can  be 
made  of  a  more  uniform  thickness  for  the  reason  that  the 
temperature  of  the  freezing  surface  is  more  uniform. 

In  a  direct  expansion  plant  the  freezing  surface  that  is  not 
backed  with  the  liquid  ammonia  will  have  one  temperature,  and 
the  freezing  surface  that  has  gas  inside  of  it  will  have  an  entirely 
different  temperature,  and  the  range  is  considerable. 

The  cbiffioulty  with  the  brine  plants  is  the  impossibility  of  mak- 
ing plates  that  won't  leak.  The  displacement  per  ton  for  the 
compressors  of  a  brine  plant  is  less  than  the  direct  expansion 
plants. 

If  the  expansion  coils  can  be  kept  very  nearly  flooded  with 
liquid  we  obtain  a  higher  efficiency  and  a  more  uniform  tem- 
perature. 

The  difficulty  with  the  direct  expansion  plant  is  the  ammonia 
leaks;  the  expansion  coils  being  subject  to  such  a  range  of 
temperatures.  The  loss  of  ammonia  on  a  direct  expansion  plant 
is  considerably  more  than  on  a  brine  plant. 

If  we  use  brine,  we  will  have  to  use  a  slightly  lower  back  pres- 
sure than  if  we  use  direct  expansion.  Few  brine  plants  are  running 
at  much  better  than  10  or  12  pounds  back  pressure,  whereas  the 
direct  expansion  plant  will  run  higher.  The  accumulator  system 
will  run  as  high  as  14  or  16  pounds. 

Plate  ice  can  be  made  as  pure  as  any  can  ice  ever  produced. 
There  are  two  means  at  hand  to  accomplish  this  end: 

Sterlization  and  Ozonization. — Where  plenty  of  exhaust  steam 
is  at  hand,  sterilization  is  the  best  means,  but  in  most  plants 
ozonization  will  be  found  the  more  convenient  method. 

Treatment  by  ozone  will  reduce  the  number  of  bacteria  from 
3,000  to  7  per  cubic  centimeter,  and  the  7  remaining  bacteria 
are  of  the  harmless  kind.  The  investment  runs  from  $12  to  $20 
per  ton  of  ice-making  capacity,  including  filters;  the  power  re- 
quired is  about  one  H.  P.  per  hr.  The  German  standard  for 
pure  potable  water  is  100  bacteria  per  cubic  centimeter.  The 
treatment  would  therefore  more  than  meet  the  requirements  of 
the  health  board. 

A  sterilizing  equipment  is  both  higher  in  first  cost  and  cost 
of  operation,  and  has  the  added  disadvantage  of  sending  the  water 
to  the  forecooler  at  a  considerably  higher  temperature. 

Plate  System  vs.  Can  System. 

The  principal  elements  in  the  selection  of  "plate"  system  and 
"can"  system  contrasted: 


PLATE  JCE  PLANTS. 


END  EtP' 
FIG.    47.     20-TON     PLATE    ICE    PLANT. 

Quality  of  Ice. — Both  systems  under  intelligent  management 
will  produce  ice  of  good  quality,  but  the  "can"  system  depends 
upon  a  complicated  arrangement  of  distilling  and  filtering  appara- 
tus which  permits  rapid  deterioration  in  quality  if  not  carefully 
watched  and  kept  in  effective  working  condition. 

Power. — Water,  gas,  electricity  or  any  cheap  motive  power  can 
be  used  for  producing  plate  ice,  but  when  distilled  water  is 
required,  the  "can"  system  must  use  steam. 

Water. — Where  water  is  highly  impregnated  with  lime,  etc., 
or  gaseous  products  capable  of  vaporization  and  condensation, 
the  "plate"  system  can  be  used  if  operated  at  a  slow  rate  of 
freezing,  as,  for  instance,  sea  water  can  be  frozen  on  the  "plate" 
system  while  very  opaque  and  difficult  to  handle  on  the  "can" 
system. 


PLATE  ICE  PLANTS. 


105 


Investment  or  First  Cost. — For  producing  ice  12  to  14  inches 
thick,  the  investment  is  greater  in  the  "plate"  than  in  the 
"can"  system,  where  steam  is  used,  by  33  to  75  per  cent.  This 
is  due  largely  to  the  increased  area  of  buildings  required,  high 
pressure  compound  condensing  steam  engines,  power  traveling 
cranes,  expensive  construction  of  freezing  tanks  and  cells,  etc. 

Cash  Available. — Given  a  limited  cash  capital  you  are  enabled 
for  one-half  the  money  to  buy  and  equip  a  "can"  system  of  same; 
tonnage  capacity,  occupying  but  one-half  the  space.. 

Ice  for  Cooling  Cars. — When  crushed  ice  is  required!  solely  for 
cooling  purposes,  the  "can"  system  is  by  all  means  the  cheapest 


END  ELEVATION 
FIG.    48.     50-TON    PLATE    ICE    PL<ANT, 


io6  PLATE  ICE  PLANTS. 

to  operate,  as  the  ice  may  be  made  in  thin,  quick-freezing  moulds, 
the  distilling  system  and  steam  boiler  dispensed  with,  and  any 
motive  power  used  for  driving  the  compressor. 

To  secure  best  economy  in  large  "plate"  system  installation, 
the  equipment  should  include  power  hoisting  crane  for  lifting 
ice  from  tanks;  automatic  machinery  for  sawing  large  cakes  into 
blocks;  power  ice  handlers  and  conveyors;  ample,  well  insulated 
ice  storage  rooms;  the  main  tank  freezing  cells,  plates  or  coils 
thoroughly  well  made  with  a  view  to  long  life  and  avoiding  leak- 
age; abundant  fore-cooling  water  storage.  Where  steam  must  be 
used,  adopt  high  pressure  water  tube  boiler  and  best  make  of 
compound  condensing  engine,  preferably  of  the  Corliss  type. 
(Penny.  Trans.  A.  S.  R.  E.  1906.  Abridged.) 

NOTES  ON  ICE  PLANTS  : 


Pipe  Lime  Refrigeration 

(J.   EJ.   Starr,  A.   S.   R.   E.     Trans.    1906.     Abridged.) 

Pipe  lines  are  laid,  by  virtue  of  public  franchise,  under  the  streets 
and  public  places  of  cities  for  supplying  refrigeration  to  individual 
consumers.  Two  methods  have  been  employed  for  distribution : 
(a)  Brine  Circulation;  (b)  Direct  Expansion. 

The  relation  of  income  and  length  of  main  is»on  an  average 
$12,000  gross  income  per  mile.  The  various  installations  range 
from  one  mile  of  mains  to  seventeen  miles. 

Brine  lines  have  the  usual  two  pipe  flow  and  return  system  with 
refrigerator  coils  connected  in  multiple.  The  brine  is  cooled  in 
brine  coolers  of  the  shell  and  coil  type.  Brine  pumps  are  of  the 
triplex  type  driven  by  direct  connected  engines. 

The  power  required  for  distributing  the  brine  varies  directly 
with  the  head  and  the  range  of  the  brine.  Assuming  a  range  of 
5  deg.  between  the  outgoing  and  incoming  brine  and  a  head  of  120 

200  X  120 
feet   we  have  -  -  =  0.14    H.    P.   per  ton   of   refrigeration 

5  X  33,000 

delivered   to   the  brine   as   measured   by   the   brine.      This  will   call 
for  from  0.23  to  0.28  H.  P.  at  the  motor  per  ton  of  refrigeration. 

The  insulation  of  the  mains  is  effected  by  laying  the  pipe  in  a 
wooden  box  and  covering  with  an  insulating  material  soaked  in 
some  moisture  resisting  compound.  (Hair  felt  soaked  with  a  mixture 
of  rosin  and  paraffin  oil  or  granulated  cork  soaked  in  pitch.)  Above 
ground  all  service  lines  must,  of  course,  be  insulated  to  and*  from 
the  wall  of  the  refrigerator. 

The  loss  of  refrigerating  power  by  reception  of  heat  coming 
through  the  insulation  of  mains  is  constant  on  a  given  length  of 
main  for  each  division  of  temperature  of  the  atmosphere,  but  varies 
directly  :  as  to  percentage  of  total  load,  with  the  load — that  is,  the 
greater  the  load  the  less  the  percentage  of  loss— accurate  ther- 
mometer readings  of  brine  temperature  in  the  mains  at  the  station 
and  at  various  points  on  the  line  are  needed  to  establish  this  point. 

Ammonia  lines  have  been  laid  under  the  three-pipe  system,  con- 
sisting of  a  liquid  line  carrying  the  liquid  ammonia  under  pressure 
by  main  and  branch  to  the  expansion  valves  at  the  refrigerators ; 
a  return  or  vapor  line  carrying  back  the  gas  ;  and  a  third  line  called 
the  vacuum  line. 

The  expansion  coils  in  the  refrigerators  are  connected  in  multiple 
between  the  liquid!  and  the  vapor  line.  The  vacuum  line  is  con- 
nected at  each  expansion  coil  on  the  coil  side  of  the  stop  valves  on 
the  liquid  and  vapor  lines.  Repairs  at  any  refrigerator  can  thus 
be  made  without  disturbing  the  balance  of  the  system.  The  vacuum 
line  is  also  connected  at  manholes  for  repair  purposes  on  the  main 
lines.  It  can  be  used  as  a  bridge  line  to  carry  liquid  over  a  block 
where  there  may  be  a  leak  on  the  liquid  line.  Its  use  is  also  imper- 
ative in  extensions  of  existing  lines  to  carry  air  or  ammonia  to  test 
out  new  lines  without  disturbing  the  operation  of  old  ones.  The 
ammonia  lines  are  laid  in  a  condxiit  of  vitrified  or  salt  glazed  split 
sewer  pipe.  The  lower  half  of  the  conduit  being  first  laid  in  con- 
crete, then  the  ammonia  lines  are  run  and  tested,  then  the  top  half 
of  the  conduit  is  laid  on  and  cemented.  Manholes  are  provided  at 
street  intersections  in  the  usual  manner  of  all  street  service  work. 

The  expansion  piping  is  rather  liberally  installed,  the  idea  being 
to  have  enough  piping  to  superheat  the  gas  to  nearly  the  tempera- 
ture of  the  box  and  prevent  frosting  out  into  the  return  main. 

In  small  refrigerators  it  is  very  difficult  to  prevent  frosting  out, 
and  wherever  possible  such  boxes  are  connected  in  series  with  other 
boxes.  Where  a  number  of  small  boxes  are  grouped  as  in  a  hotel 


io8  PIPE  LINE  REFRIGERATION. 

or  restaurant,  a  brine  cooler  is  installed,  fed  from  the  street  lines, 
and  brine  circulation  is  used  locally. 

Laying  out  the  central  station  as  to  tonnage  of  machinery  and 
provision  for  increase  involves  a  study  of  average  weather  condi- 
tions. The  annual  output  must  be  divided  into  periods  showing 
average  demands  by  periods  and  of  course  the  plant  must  be  ma- 
chined for  the  highest  daily  load  and  for  the  absolute  peak.  By 
taking  the  average  mean  monthly  temperatures  and  subtracting 
from  each  monthly  mean  the  figure  30  (a  little  below  freezing)  the 
remainders  will  represent  the  distribution  of  the  load  by  months. 
Working  these  figures  into  percentages  of  the  total  we  have  our 
monthly  load  curve. 

For  laying  out  piping  for  the  distribution  of  liquid,  a  drop  in 
pressure  between  the  condenser  pressure  and  the  pressure  due  to 
the  highest  temperature  likely  to  exist  at  any  point  on  the  liquid 
line  is  to  be  taken  as  basis  for  friction  head.  As  most  installations 
so  far  are  on  comparatively  level  ground,  static  pressure  has  not 
figured  extensively,  but  it  carries  a  limitation  if  liquid  lines  running 
to  the  upper  stories  of  high  buildings  are  involved.  Such  lines  can 
not  be  carried  to  a  height  where  the  loss  of  head  would  involve  a 
pressure  below  the  boiling  point  of  the  liquid  at  the  temperature 
surrounding  the  pipe. 

The  temperature  of  the  mains  in  the  conduit  seldom  rises  above 
75°  in  the  summer.  This  corresponds  to  an  ammonia  pressure  of 
126.5  Ibs.  With  a  condensing  temperature  of  150  Ibs.  the  distribu- 
tion of  a  given  tonnage  or  its  corresponding  amount  of  liquid  could 
be  calculated  on  a  d"rop  of  23.5  Ibs.  In  practice  a  drop  of  15  Ibs. 
has  been  considered  about  the  outside  allowance  for  friction  head. 
There  always  remains  in  case  of  change  of  conditions  the  alternative 
of  raising  the  condenser  pressure  to  keep  the  ammonia  in  liquid 
form  up  to  the  expansion  valves. 

It  is  desirable  to  hold  the  back  pressure  at  the  station  as  low  as 
possible  in  order  to  obtain  the  greatest  available  friction  head,  thus 
keeping  down  the  cost  of  line  and  also  retaining  the  ability  to  give 
low  temperatures  at  refrigerators  far  from  the  station  and  to  keep 
down  the  cost  of  expansion  piping.  For  this  reason  the  absorption 
type  of  machine  has  been  used  largely  for  pipe  line  systems  as  it 
possesses  the  advantage  of  working  with  economy  at  low  back 
pressures. 

Avoiding  freezing  business  all  other  classes  of  refrigeration,  say 
from  28°  up,  can  be  carried  on  the  basis  of  25  pounds  for  the  high- 
est pressure  on  the  return  line  and1  5  to  10  Ibs.  at  the  station,  giving 
a  friction  head  of  from  15  to  20  Ibs. 

In  July  and  August  one  ton  of  refrigeration  takes  care  of  2,800 
cubic  feet  of  space.  One  cubic  foot  of  space  requires  .07  ton  per 
annum.  One  square  foot  of  insulation  requires  .204  ton  per  annum. 

The  most  important  question  in  direct  expansion  pipe  line  work 
is  that  of  leakage  of  ammonia.  In  fact,  experience  has  shown  that 
the  financial  success  of  the  system  must  stand  or  fall  on  this  item. 
Various  methods  have  been  tried  ;  finally  a  system  was  adopted  of 
anchoring  the  pipes  at  definite  intervals  with  expansion  joints  at 
definite  distance  from  each  anchor,  confining  the  expansion  and  con- 
traction to  definite  distances  and  to  calculable  limits.  The  later 
developments  include  welding  the  pipes  in  a  continuous  length  from 
manhole  to  manhole  and  putting  expansion  joints  at  the  manhole 
or  U  bends  on  the  run. 

Of  late,  apparently  successful  attempts  have  been  made  to  weld1 
the  pipes  in  situ  by  the  thermit  welding  process.  This  process 
consists  in  thoroughly  cleaning  the  ends  of  the  pipes  and  butting 
them  together.  Strong  clamps  hold  the  ends  firmly  one  to  the  other. 
An  iron  mould  is  then  clamped  around  the  pipe  having  an  annular 
opening  all  around!  the  joint.  The  thermit  is  then  poured  into  the 
mould  from  a  hand  crucible.  The  lighter  slag  first  pours  out  of  the 


AUTOMATIC  MACHINES. 


109 


mould,  followed  by  thermit  steel,  which  sinks  to  the  bottom,  filling 
the  mould  about  half  way  up  with  steel,  and  the  displaced  slag  fills 
the  balance  of  the  mould.  The  great  heat  of  the  thermit  brings  the 
metal  of  the  pipe  to  a  welding  heat.  The  clamps  are  d*rawn  towards 
each  other,  compressing  the  butted  ends  of  the  pipe,  and  the  weld 
is  complete. 

While  undoubtedly  the  major  cause  of  loss  from  leakage  has  re- 
sulted from  worn  out  or  badly  put  together  joints  in  the  line,  as  a 
result  of  expansion  and  contraction,  there  will  always  remain  a 
certain  amount  of  what  might  be  termed  insensible  leakage.  While 
this  will  doubtless  always  exist,  its  aggregate  will  not  be  sufficient 
to  cut  a  large  figure  in  line  expense. 


Automatic  Refrigerating  Machines 

In  the  last  few  years  a  machine  has  been  put  on  the  market 
which  is  said  to  be  automatic  and  which  may  be  adapted  to  any 
small  compressor.  The  accompanying  diagram  shows  the  arrange- 
ments of  these  parts. 

The  switchboard  is  equipped,  with  the  motor-controlling  rheostat, 
switches,  voltmeter,  ammeter  and  scale  light,  with  terminal  con- 


FIG.    49.     AUTOMATIC    REFRIGERATING    MACHINE. 

tacts  for  all  wire  connections  on  the  back  of  this  panel.  The  ther- 
mostat in  the  refrigerator  is  adjusted  to  operate  at  any  two  tem- 
peratures :  one,  above  which  the  temperature  in  the  box  must  be 
allowed  to  rise ;  and  the  other,  below  which  it  must  not  fall. 

After  the  plant  has  been  started  it  will  operate  until  the  lower 
or  cold  limit  of  temperature  has  been  reached  in  the 
refrigerator.  Electric  contact  is  then  made  in  the  thermostat, 
automatically  opening  the  switch  so  as  to  stop  the  motor.  The 
stopping  of  the  process  of  refrigeration  results  in  the  gradual  rise 
of  temperature  in  the  refrigerator  to  the  higher  limit,  when  electric 
contact  is  made  in  the  thermostat  automatically  closing  the  switch 
and  starting  the  motor  again. 

As  a  rule  the  thermostat  is  adjusted  so  that  the  plant  will  operate 
and  produce  refrigeration  within  a  range  of  3°  to  4°  of  variation  in 
the  refrigerator  ;  in  other  words,  if  the  minimum  of  36°  is  desired 
the  plant  will  operate  until  this  temperature  is  obtained,  when  it 


no  AUTOMATIC  MACHINES. 

will  stop  and  not  operate  again  until  the  temperature  rises  to  39° 
or  40°,  according  to  the  adjustment  of  the  thermostat. 

While  in  operation  the  motor  and  compressor  are  'both  working 
at  full  load  and  highest  efficiency,  and  when  stopped  all  expense  of 
operation  ceases. 

The  Automatic  Expansion  Valve  is  regulated  in  the  following 
manner  : 

Within  the  valve  chamber  is  fitted1  an  accurately  constructed 
valve  mechanism  which  will  only  allow  a  feed  of  the  liquid  from 
the  compression  side  of  the  system  into  the  expansion  side,  when 
the  vapor  pressure  of  the  expansion  side  is  less  tban  an  adjustable 
and  opposed  pressure.  The  proper  proportion  of  feed  to  meet  the 
requirements  of  refrigeration  in  each  specific  plant  can  always  be 
determined  and  regulated  by  the  adjustment  provision. 

Perfect  regulation  by  this  automatic  valve  is  insured  by  the 
thermostat  control  of  the  motive  power,  stopping  the  plant  when 
the  temperature  has  fallen  to  the  desired  limit. 

The  Automatic  Water  Regulator  allows  the  pressure  in  the  con- 
denser pipes  to  act  against  a  flexible  diaphragm,  which  in  turn 
actuates  the  valve  stem  or  plunger  in  the  chamber  of  this  regu- 
lator ;  the  reverse  action  being  that  of  a  tension  spring  adjusted* 
to  prevent  a  flow  of  water  when  the  pressure  in  the  condenser  is 
reduced  below  the  normal,  that  is,  when  the  plant  has  been 
stopped. 

The  water  circuit  is  provided  with  a  by-pass  connection,  hand 
controlled,  to  permit  a  flow  of  water  at  other  times,  for  example, 
to  flush  the  water  circuit  when  the  plant  has  been  out  of  service 
for  a  long  period  as  it  might  be  during  cold  weather. 

The  Automatic  High-pressure  Cut-off  is  attached  to  the  high- 
pressure  gauge  and  is  so  arranged  that  if  the  pressure  of  the  con- 
denser, as  indicated  by  the  gauge,  should  for  any  cause  rise  far 
above  its  normal,  then  the  thermostat  circuit  is  automatically  in- 
terrupted so  as  to  open  the  motor  switch  and*  stop  the  operation  of 
compression. 

When  the  pressure  falls  to  the  normal  or  predetermined  level, 
the  mechanism  restores  the  control  of  the  plant  to  the  thermostat, 
which  in  turn  will  start  or  stop  the  motor-driven  compressor  in 
accordance  with  the  temperature  conditions  in  the  refrigerator. 
When  the  pressure  cut-off  operates  to  shut  down  the  plant  a  special 
signal  gong  is  automatically  sounded  to  indicate  the  cause  as  being 
abnormal,  and  an  auxiliary  bell,  on  a  primary  battery  circuit,  can 
be  placed  at  a  distance  so  as  to  indicate  each  stopping  of  the  plant 
from  this  cause,  if  the  water  supply  should  be  irregular. 

The  compressor  shown  in  the  present  illustrations  is  built  by  the 
Automatic  Refrigerating  Company  of  Hartford,  Conn. 


PART   IV— OPERATION   OF  COMPRESSION 
PLANT 


Erection  and  Management 

The  installation  of  the  plant  comprises  the  proper  erection  of 
machine  and  apparatus,  testing  the  different  parts  under  air  pres- 
sure and  charging  the  system,  after  which  an  efficiency  test  is 
made. 

Foundation. 

The  foundation  for  engine  and  compressor  must  be  finished  at 
least  two  weeks  before  setting  the  machines.  The  icllowing  rules 
should  be  strictly  observed: 

Digging. — Dig  down  to  a  good,  solid  bottom,  which  is  never  to 
be  less  than  called  for  on  drawing.  Break  and  remove  adjacent 
rocks,  to  avoid  vibration.  Depth  of  foundation  varies  from  5  to 
8  ft.  for  small  and  medium  sized  machines.  As  a  general  rule, 
the  foundation  shall  weigh  approximately  5  times  as  much  as 
machine. 

Concrete. — For  the  concrete,  only  Portland  cement,  sharp  and 
clean  stones  and  sand  are  to  be  used.  It  is  to  consist  of  1  part 
cement,  3  parts  sand,  5  parts  stone. 

The  concrete  is  to  be  well  rammed  down  and  is  to  have  a  level 
surface.  The  template  should  set  square  and  approximately  level. 
The  bolts  must  firmly  fit  the  washers  and  are  then  blocked  up 
and  adjusted  with  the  nuts,  until  the  bolt  ends  are  level  with 
each  other  and  at  the  right  height  above  engine  house  floor. 
Around  the  bolts,  beginning  within  12  inches  from  the  anchor 
plates,  a  space  4  X  4  is  to  be  left  clear  of  mortar  and  other 
material,  or  the  bolts  are  encased  in  a  pipe  about  4  inches  diam., 
which  is  removed  before  machine  is  put  in  place. 

Surrounding  Buildings  or  Posts. — The  concrete  should  not  touch 
any  surrounding  parts  of  the  building  or  post  foundations,  should 
not  bind  on  any  pipes  or  other  structure,  and  the  contractor  has 
to  make  sure  that  no  damage  can  be  done  by  vibration  of  machine. 

Grouting. — After  machine  is  in  place,  grout  with  either  cement, 
sulphur  or  iron  rust.  For  cement,  mix  equal  parts  of  Portland1 
cement  and  sharp  sand.  Add  water  to  make  a  thin,  freely  run- 
ning grout.  Build  up  one  layer  of  bricks  around  bed  plate  and 
foot  of  machine,  then  pour  in  cement,  until  it  sets  solid  underneath 
and  about  half  or  one  inch  up  on  the  casting.  It  will  be  dry  and 
set  properly  in  two  or  three  days.  When  using  sulphur,  make  a 
stiff  clay  around  bed  plate,  melt  sulphur  in  a  large  pot  over  a 
slow  fire  and  pour  quickly  with  the  hand  ladle  (boils  at  239°). 

Pipe  Connections. — They  are  usually  laid  out  carefully  in  the 
drawing  and  made  up  in  the  shop,  measuring  not  over  4  ft.  one 
way  and  20  ft.  the  other  way.  All  joints  on  ammonia  pipes  are 
screwed  and  soldered  except  on  some  final  connections,  which 
must  be  fitted  on  job.  Suitable  hangers  must  be  provided  accord- 
ing to  character  of  walls  and  ceiling. 

Testing  Plant. 

It  is  important,  before  introducing  the  charge  of  gas  into  the 
machine  system,  to  carefully  test  every  part  of  the  apparatus, 
and  make  it  thoroughly  tight  under  at  least  300  pounds  air  pres- 
sure, which  pressure  may  be  obtained  by  working  the  ammonia 
compressor  and  allowing  free  air  to  flow  into  suction  side  of 
pump  by  opening  special  valves  provided  for  this  purpose,  the 
entire  system  being  thus  filled  with  compressed  air  at  the  desired 


H2    OPERATION  OF  COMPRESSION  PLANT. 

pressure.  While  this  pressure  is  being  maintained,  a  search  Is 
instituted  for  leaks,  every  pipe,  joint,  and  square  inch  of  surface 
being  tediously  scrutinized.  One  method  is  to  cover  all  surfaces 
with  a  thick  lather  of  soap,  leaks  showing  themselves  by  forma- 
tion of  soap  bubbles.  In  the  case  of  condenser  and  brine  tank 
coils,'  the  tanks  are  allowed  to  fill  with  water,  the  bubbles  of  air 
escaping  through  the  water  locating  the  leak.  It  is  important 
that  the  apparatus  be  thoroughly  tight,  and  while  each  separate 
piece  is  carefully  tested  in  the  works,  transportation  and  handling 
may  damage,  besides  a  few  joints  are  made  on  the  premises,  and 
it  is  necessary  to  go  over  the  entire  surface  to  be  sure.  While 
the  machine  is  engaged  in  pumping  air  into  the  system,  advantage 
should  always  be  taken  of  this  opportunity  to  purge  the  system,  of 
all  dirt  and  moisture.  To  do  this  properly,  valves  are  provided  so 
the  apparatus  may  be  blown  out  by  sections,  removing  valve 
bonnets,  loosening  joints  for  this  purpose,  so  that  it  is  positively 
known  that  each  pipe,  valve  and  space  is  strictly  clean  and 
purged  of  all  dirt  and  traces  of  moisure. 

A  final  test  may  then  be  had  by  pumping  a  pressure  of  300 
pounds  upon  the  entire  system,  and  allowing  the  apparatus  to 
stand  for  some  hours,  estimating  the  leakage,  if  any,  by  noting 
the  degrees  of  pressure  as  shown  by  the  pressure  gauge  connected 
to  system.  The  air  pressure  will  shrink  somewhat  at  first,  by 
reason  of  losing  heat  gained  during  compression  by  the  pumps 
As  soon  as  the  air  parts  with  its  heat  and  returns  to  its  normal 
temperature,  the  gauge  will  come  to  a  standstill  and  remain  at  a 
fixed  point  (depending  upon  the  barometer  and  changing  tempera 
ture  of  the  room),  if  the  system  is  tight. 

Do  not  cJiarge  the  system  until  it  is  well  cleansed,  purged 
and  tight. 

After  machinery  has  been  made  perfectly  tight,  air  must  be  ex- 
hausted from  the  entire  system  by  working  the  pumps  and1  dis- 
charging the  air  through  the  valves  provided  for  this  purpose. 
When  the  escape  of  air  ceases  and  the  pressure  gauges  show  a 
full  vacuum,  it  is  well  to  close  all  outlets  and  allow  the  machinery 
to  stand  for  some  time,  to  test  the  capacity  of  the  apparatus 
to  withstand  external  pressure  without  leakage;  in  some  cases  it 
has  been  discovered  that  parts  while  tight  from  internal  pressure, 
owing  to  loose  particles  lodging  over  leaks  and  acting  as  plugs 
to  prevent  escape,  these  same  points,  when  subjected  to  an  external 
pressure,  give  way  and  disclose  the  leakage. 

Charging   Plant. 

Connect  the  flask  of  ammonia  to  the  charging  valve,  the  gauge 
still  showing  a  vacuum,  close  the  expansion  valve  in  main  liquid 
pipe  connecting  receiver  to  brine  tanks.  Then  open  valve  on 


FIG  50. 

Position  of  the  tank  should  be  as  in  Fig  50,  the  outlet  valve  pointing 
upwards  and  the  other  end  of  the  tank  raised  12"  to  15".  The  connection 
between  the  outlet  valve  of  the  tank  and  the  inlet  valve  of  the  system 
should  be  a  %"  pipe. 


OPERATION  OF  COMPRESSION  PLANT.    113 

ammonia  flask  and!  allow  the  liquid  to  be  exhausted  into  the  system. 
We  recommend  placing  the  flask  on  small  platform  scales,  in  order 
to  weigh  the  contents  and  know  positively  wh&n  cask  is  exhausted. 
Eiach  standard  tank  contains  from  100  to  110  Ibs.  of  ammonia. 

The  machine  may  be  run  all  this  time  at  a  slow  speed,  with 
discharge  and  suction  valves  wide  open.  As  one  flask  is  exhausted, 
place  another  on  scales,  and  continue  until  the  liquid  receiver 
Is  shown  to  be  partly  full,  by  the  glass  gauge  thereon.  Then 
shut  the  charging  valve  and  open  and  regulate  the  main  expansion 
valve;  the  machine  is  then  sufficiently  charged  to  do  work,  as 
shown  by  the  pressure  gauges  and  gradual  cooling  of  the  brine 
and  frosting  of  expansion  pipe  leading  to  brine  tank  colls. 

While  the  system  is  being  charged,  water  is  allowed  to  flow  over 
the  condenser,  and  time  diligently  employed  in  searching  further 
for  leaks,  which  can  readily  be  detected  by  sense  of  smell,  each 
point  being  again  gone  over. 

Ammonia  is  a  great  solvent,  and  in  some  cases  leaks  may  be 
opened  up  by  reason  of  the  gas  dissolving  substances  that  may 
have  stopped  defective  places  and  withstood  the  air  test. 

Amount  of  liquid  in  system  : 

Tons  of  refr.  in  24  hrs. .  5  10  15  20  25  50  100  150  200 
Lbs.  of  liquid 150  200  250  350  375  425  500  550  750 

Add  to  the  above  one-third  Ib.  for  1  ft.  of  2-inch  expansion 
pipe.  Sulphur  dioxide  machines  use  about  3  to  4  times,  and 
carbonic  acid  machines  5  to  6  times  as  much  liquid. 

Air  in  the  System. — -Negligence  in  regulating  the  expansion  valve 
and  needlessly  pumping  a  vacuum  on  the  brine  tank,  carelessly 
allowing  leaky  stuffing  boxes,  may  allow  air  to  got  into  the  sys- 
tem, as  will  also  taking  the  apparatus  apart  without  expelling  the 
air,  before  the  re-introduction  of  the  ammonia  gas. 

The  presence  of  air  in  considerable  quantity  is  readily  noticed 
by  an  expert,  by  the  intermittent  action  of  the  expansion  valve 
and  singing  noise,  rise  of  condensing  pressure,  loss  of  efficiency 
in  the  condenser,  etc.  Purging  valves  are  provided  on  the  con- 
denser and  other  points  to  allow  the  imprisoned  air  to  escape, 
and  restore  the  apparatus  to  its  normal  condition  of  pressure  and 
efficiency. 

Pumping  Out  Connections. 

Every  compressor  should  be  provided  with  a  by-pass,  which 
enables  the  engineer  to  exhaust  the  ammonia  from  any  part  of  the 
system,  and  temporarily  store  it  in  any  other  part  until  the  re- 
pairs or  examinations  are  made. 

The  by-pass  is  also  used  for  exhausting  the  compressors  them- 
selves before  the  heads  are  removed  for  examination.  By  these 
means  we  are  able  to  reverse  the  action  of  the  pumps  and  exhaust 
the  ammonia  from  the  condenser,  storing  it  in  the  expansion  coils. 

In  each  case,  after  the  examination  of  any  part,  the  air  may 
be  exhausted  therefrom  and  the  charge  of  ammonia  re-introduced 
without  the  admixture  of  air. 

While  the  same  rules  apply  to  all  compressors,  we  append  here 
some  directions  governing  specific  makes,  as  given  by  their 
builders. 

Directions  for  Safety  Head  Compressors. 

To  pump  out  compressor  B.— All  valves  closed.  Open  main 
discharge  stop  valve  Al  and  by-pass  valves  2  and  3.  Run  machine 
slowly  until  compressor  cylinder  is  exhausted,  then  close  by- 
pass valve  3  and  cylinder  head  may  be  removed.  After  replacing 
cylinder  head  the  air  may  be  expelled  by  closing  main  stop  valve 
Al  and  discharging  through  purging  valve  on  head  of  cylinder  A. 


H4    OPERATION  OF  COMPRESSION  PLANT. 


MmSpFK^^^ 

/i'U^  •--"V  "'CHARGE       '  < 


FIG   51  —  BY-PASS   OF   SAFETY   HEAD    COMPRESSOR. 

To  pump  out  compressor  A,  proceed  in  same  manner,  using 
opposite  set  of  valves. 

To  pump  oiit  ammonia  condenser  and  store  in  evaporating  coils 
or  low-pressure  side:  Open  main  discharge  stop  valve  Ai,  by- 
pass valves  1  and  4,  thus  connecting  to  suction  of  cylinder  B, 
and  expelling  gas  by  opening  by-pass  valves,  2,  5  and  7  into  main 
suction  pipe.  Run  machine  slowly. 

By  using  oposite  set  of  valves  the  other  cylinder  may  be  used, 
as  one  is  used  to  exhaust  '  the  gas  from  the  discharge  through 
by-pass,  while  the  others  expels  it  through  the  other  portion  of 
by-pass  into  the  suction  pipe  and  low-pressure  side. 

Directions  for  "Oil"  Compressors. 

To  Pump  Out  a  Condenser.  —  Close  cocks  4,  5,  6  and  8  of 
those  condensers  which  you  don't  want  to  pump  out.  Close  cocks 
40  and  44  of  those  condensers  you  want  to  pump  out,  the  other 
condensers  wrorking  during  all  this  time.  Open  cock  1  and  then 
close  main  liquid  cock  36  and  main  return  cock  42  and  run  at 


FIG  52— PUMPING-OUT  CONNECTIONS  OF  OIL  COMPRESSOR. 


OPERATION  OF  COMPRESSION  PLANT.     115 

reduced  speed.  Now  lower  your  back  pressure  to  0  Ibs.  and  keep 
it  there  until  there  is  no  more  frost  on  the  condensers  you  want 
to  pump  out.  Don't  cut  off  the  water  from  the  condenser  you  want 
to  pump  out.  Now  close  cock  8  of  the  condenser  in  question ; 
furthermore,  cock  1,  and  open  cocks  4,  5,  6  and  cock  8  of  the 
other  condensers.  You  can  now  break  any  joint  of  the  condenser 
in  question. 

When  the  joints  of  the  condenser  have  been  made  again,  open 
cock  44  of  the  condenser  in  question  a  little,  allowing  the  air  to 
escape  at  joint  of  cocks  near  condenser.  When  you  srnell  am- 
monia strongly  close  this  joint  and  open  cock  44  fully;  further, 
cocks  8  and  40  and  your  condenser  is  in  proper  working  order. 

To  pump  out  main  liquid  line. — Close  cock  36  and  also  all  the 
expansion  cocks  but  one.  Also  close  all  the  return  cocks  except 
the  one  corresponding  with  the  expansion  cock  that  was  left 
open,  and  reduce  the  back  pressure  to  0  Ibs.,  and  keep  it  there 
as  long  as  the  pipe  shows  frost.  Then  close  the  last  expansion 
cock  and  stop  the  machine.  You  can  now  break  any  joint  of  this 
pipe,  but  you  must  not  touch  any  cock  connecting  with  it.  When 
all  the  joints  have  been  made  tight  again,  open  cock  36  a  little 
and  allow  the  air  confined  in  the  pipe  to  escape  at  the  farthest 
joint  broken  until  you  smell  ammonia  strongly.  Then  close  the 
joint,  and  you  are  ready  to  start  the  machine. 

To  Pump  Out  Brine  Cooler,  Beer  Cooler,  Etc. — Close  expansion 
cock  leading  to  the  cooler  or  cellar  you  want  to  pump  out  and  see 
that  the  corresponding  return  cock  is  open.  Close  main  liquid 
cock  36  and  all  other  2-inch  return  cocks,  and  then  reduce  your 
back  pressure  to  0  pounds,  until  it  will  not  go  up  again  when 
you  stop  the  machine  or  when  you  run  the  machine  at  its  slowest 
speed.  Then  close  the  return  cock  mentioned  before,  and  you  can 
now  break  any  joint  of  the  cooler  or  cellar  expansion,  not  touch- 
ing the  cocks.  The  machine  may  be  working  during  this  time 
and  doing  work  in  the  other  cellars  or  coolers.  If  you  want  it 
to  do  this,  open  all  2-inch  return  cocks  except  the  one  belonging 
to  cooler  or  cellar  you  wish  to  repair,  and  open  cock  36  again, 
allowing  the  back  pressure  to  go  up  to  its  usual  height.  When  all 
your  joints  have  been  made  again,  open  the  expansion  cock,  before 
closed,  a  little,  so  as  to  allow  some  ammonia  to  enter  the  cooler 
or  cellar,  and  then  close  it  again,  allowing  the  air  to  escape  ac 
the  joint  of  the  respective  cooler  or  cellar  near  return  cock  until 
you  smell  ammonia  strongly.  Then  close  the  joint  and  open 
the  respective  return  cock.  You  can  now  expand  again  in  this 
cooler  or  cellar. 

Pumping  out  storage  tank,  separating  tank,  etc.,  is  done  in 
similar  manner  and  no  further  instructions  are  required. 


Efficiency  Test  of  Refrigerating  Plant 


The  purpose  of  the  test  is  to  determine  how  the  refrigeration 
produced  compares  with  the  amount  of  work  expended  and!  the 
amount  of  coal  consumed. 

Getting  ready  for  test : 

1.     Engine  and  compressor  have  to  be  provided  with  indicators. 

2.  Condensing  water  and  circulated  brine  have  to  be  connected 
with  a  meter. 

3.  Temperature  of  in  and  outgoing  brine  and  condensing  water- 
is  to  be  measured  by  thermometers. 

4.  Also  temperature  of  ammonia  gas,  by  placing  mercury  wells 
In  the  suction  and   discharge  pipe  near  the  compressor. 

Indicator  Diagram. 

The  diagram  shows: 

(a)  The  actual  work  done  by  (engine)  or  applied  to  (compressor) 
a  piston  during  each  stroke.  H.  P.  of  compressor  Is  product  of 
mean  pressure,  piston  area  and  piston  speed  divided  by  33,000. 

The  mean  pressure  in  the  compressor  may,  in  the  absence  of  an 
indicator  diagram,  be  found  approximately  in  the  following  table. 

MEAN    PRESSURE    IN     COMPRESSOR. 


Cocdenaer  Pressure. 

103 

115 

127 

139 

153 

168 

184 

200. 

218 

Condenser  Tem- 
perature. 

65° 

70° 

75° 

80° 

85° 

90° 

95° 

100° 

105° 

Pmiun 

£= 

41.46 

43  91 

46  34 

48  77 

51.23 

63.68 

56.11 

58  64 

60  99 

4 

-20° 

6 

-15° 

42.72 

45  38 

47  90 

iO  74 

53.40 

5608 

5886 

61  40 

64  08 

9 

44.40 

47  38 

50.33 

5329 

56.25 

59.20 

62.16 

65.14 

68  09 

13 

—  5° 

45  86 

49  15 

52  42 

55  70 

5R.97 

62.25 

65.53 

68  81 

72.08 

16 

0° 

46  94 

50  56 

54  16 

57  78 

61  40 

65  00 

68.62 

'72.22 

75  84 

20 

5° 

47  74* 

51  73 

55  70 

69  68 

63  67 

67  66 

71  62 

75  61 

79  61 

| 

24                 10° 

48  04 

5240 

56  77 

61  13 

65  51 

69  86 

74.24 

78  59 

82  97 

28                15° 

47  88 

52  67 

57  44 

62.23 

67  02 

71  81 

76  60 

81  39 

86.18 

33 

20° 

47  08 

52  30 

57  53 

62  75 

67.98 

73.23 

78.46 

83  68 

88  91 

39 

25° 

45  06 

ii.34 

57  05 

62  75 

68.46 

74  17 

79.88 

85  58 

91  29 

45 

309 

43.16 

49,71 

55.92 

62  14 

68  35 

74  56 

80.77 

86  98 

93  19 

51 

55° 

40  52 

47  '26 

54.02 

60.76 

67.52 

74.28 

81  02 

87  78 

94.52 

(b)    The  conditions  of  pressure  at  the  different  positions  of  the 
piston,  the  working  of  the  valves  and  the  changes  of  temperature. 

Figs.  1  to  6  show  defective  cards. 

Figs.  7  and  8  show  good  cards. 

Fig.  9  shows  how  to  plot  the  isothermal  and  adiabatic  lines  by 
means  of  the  two  tables  below. 

To  plot  the  adiabatic  line  by  means  of  Table  I;  Find  in  the 
horizontal  line  with  p  the  number  corresponding  to  the  absolute 
back  pressure  on  your  card.  Then  in  the  same  vertical  column 
that  contains  your  absolute  back  pressure,  and  opposite  p»,  find 
the  value  of  p9.  Lay  this  off  on  line  9  (Fig.  53,  No.  9),  from  btobi, 
to  the  same  scale  as  that  of  your  indicator  spring.  Do  the  same 
for  p8,  p7  to  pi.  You  then  have  a  series  of  points  through  which 
you  draw  the  smooth  curve  a,  b,  c.  This  curve  is  the  adiabatic. 
To  plot  the  isothermal  line  by  means  of  Table  II  proceed  the 
same  as  explained  in  regard  to  the  adiabatic  line. 


EFFICIENCY  TEST  OF  PLANT.  117 

CVrate  Good     Carets 

ry  Goj 


tt. 


TABLE  I. 


TABLE  II. 


ADlABATlC    CON 


40J 


41.3 


110.8  113.2  115.8 
148.0  1513  154.6 
215.0  220.0  224.8 


«.r 


227.8  235.8  244.0 


4X,;| 


234.2  239.0  243.8  248.6 
398.0  407.0  414.0 


(Mi  il 


39.0 
45.4 
54.0 
66.2 
83.8 
111.8 
162.5 
276.3 
680.0 


85.5 
108.3 
144.7 
213.0 
357.8 
880.0 


72.1 

H5  8 
105.0 
133.0 
177.6 


P- 

P.. 
P.. 
P.I 
P.I 
P.I 
P., 
P.s 
P.I 

1? 

18. 
21   4 
25.0 
30  ( 
37  f 
50  1 
75  ( 
I50.( 

16 

17  h 
20.1 

22  i- 
26  ' 
32  ( 
40  f 
53  4 
80  I 
(ill  I 

ir 

18  9 
2-1   L 
24   I 
27  3 
34  0 
42  f 
56  7 
85  ( 
170  ( 

1* 

20  I 

22  r 

30  ( 
86  1 
45  ( 
dd   1 
90  0 

1X0    ( 

ffdff, 

23.7   25  G 
27  1    28  6 
31   7    33  4 
38  0   40  0 
47  5   50  U 
63  4    66.7 
95.0100  0 
190  olaOO-.fl 

2:1  .  ; 
26.1. 
30  ( 
35  ( 
42  ( 
52.  f 
70  1 
105  ( 
210  ( 

"Wj  «3 
24.5   25  6 
27  5   28  7 
31  4  32.8 
3d  7  38.4 
44  01  46  0 
55.0)  57  6 
73  4   76  7 
HO.  01  15  0 
220  0|230  (1 

30  O 
34.3 
40  0 
48.0 
«0.0 
80  1 
120.0 
MO.O 

P. 
P.. 

P., 

P-7 
P.. 

fit 

I 

27  8 
31  2 

35  ." 
41.7 
50  0 
(,2  f 
83.4 
125  0 
JMi  ( 

28  < 
32  f 
37  1 
43  4 
52  ( 
65  ( 
8(1  7 
30  ( 
260.1 

30  ( 
83  - 
38  t 
45  ( 

('-  ' 
BO  1 

135  0 

27(1.  ( 

31    1 
35  ( 
40  I 
46  7 
Mi  ( 
70  ( 
93  4 

110  ( 

280  ( 

32   L 
41   • 

48  : 

58  ( 
72  '. 
96  7 
145  ( 

291)  ( 

37  ; 

42  8 
50  f 
60  ( 
7.5  ( 
100   1 
150.0 

((HI    I 

34  ( 

44  : 

51   " 
62  ( 
77  f 
103   -1 
155   ( 
(1(1  ( 

35  ( 
40  ( 
45  7 
53  4 
64  ( 
80  ( 
106   ~ 
1(10.1 
32(1  ( 

3H 

36  ' 
41  2 
47  '2 
55  ( 
66.0 
82..' 
1)0.1 
165  ( 
33(1  ( 

37  8 
42.5 
48  e 
50.7 
68.0 
85  0 
113  4 
170.0 
1340  0 

1    •» 
]>•" 
]>•" 
I 

5?» 

43  7 

50  i 
58.4 
70  ( 

16  7 

75  ( 
i.SO.( 

40  ( 
45  0 
51   4 

60.  ( 
72  ( 
HO  ( 
20  1 

80.  ( 
60  ( 

4?  2 
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52  8 
61    7 
74  0 

92  5 

23   4 
85  0 

170  0 

42  3 
47  5 
54  8 
03  4 
7(1  0 
<«5  0 
126  7 

'HI  '1 

wo.o 

43  4 
48  7 
55  7 
(if.  0 
78  0 
97   5 
130.1 
195.0 

I!IO    I 

44   ,. 

50  ( 

57  L. 

80  1 
00  I 
33  4 
200  ( 
400.0 

45  d 
51  ... 

58   ( 
68  4 
82  ( 
102  : 
136  - 
205  I 
110.  1 

46 
52 

(in  i 
70  ( 
84  ( 
105  ( 
140.1 
210  I 
120  1 

47  8   48  9 
53  7   55  0 
61  4   62.8 
71  7    73  4 
86  0   88  0 
107  5'llO  0 
143  4(146  7 
215  0|220  0 
430.0'440.0 

I 
1 
1 

I 

I 
1 

P 

50  0 

56.  L 
(14  .' 
75  ( 
90  ( 
12  f 
50  I 
225  ( 
450  ( 

51   2 
57  5 
65  7 

76  - 

15  1 
53  4 
30  ( 
60.  f 

52  3 

r,8  7 

67  2 

78  .4 
94   ( 
17.5 
56   7 
235.0 
170.0 

53  4 
60  0 
68  5 
80  0 

(Hi    0 

20  (1 
60  0 
240  0 
480.0 

54  r 

6)   L 
TO  0 
81  7 

98  ( 

122.: 

163.4 

245  ( 
(90  ( 

5,5  ( 
62  f 
71  4 
83  4 

no  ( 
2;>  ( 
tit.  " 
250.  ( 
.00.0 

63   - 
72  8 
85  ( 
102  . 
127.  f 
J70  0 
255  0 
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5?, 
65  I 
74  : 
86  ' 
104  ( 
130  ( 

260  ( 

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58  < 
(1(1   L 
75  7 
88  4 
106   ( 

132.1 

176  7 
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530.  ( 

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135.0 
1800 
270  0 
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1 
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P.,     " 

61   2 

68  7 
78  f 
91  7 

10   ( 

37.5! 
83  4 
750 
80.01 

62.  3 
70  ( 
80  0 
93.4 
12.0 
40.0 
180  7 
280.0 
5GO.O 

57 

63.4 
71  2 
81.4 

96.0 

14  0 

42.5 

89  H 

70.0 

64  5 
72  5 
K2  8 
96  7 
16  0 
45  0 
93  .  4 
290  (1 

SO   0 

65  fi 
73  7 
84.3 

<M  4 
118  0 

S! 

SJ 

66  7 
75  0 
85  7 
00  0 
20  0 
50  0 

JIKI    1 
)00.0 

.110  0 

i 

RECORD  OF  A  TEST  MADE  WITH  A  "DE  LA  VERGNE"  32-TON 
MACHINE  AT  THE  PACKINGHOUSE  OF  RICHARD  WEBBER. 

Readings  were  made  every  hour  for  12  hrs.  In  succession  and 
the  average  taken. 

Brine  meter,  660  cb.  ft.  p.  hr.;  water  meter,  235  cb.  ft.  p.  hr.; 
steam  gauge,  90  Ibs. ;  back  pressure,  22  Ibs. ;  cond.  pressure,  140 


ii8  EFFICIENCY  TEST  OF  PLANT. 

Ibs. ;   number  of   rev.,   2,880  p.    hr.    --    48   p.   min.;    temp,   of   feed 
water,   165°;  brine  temp.,   initial   17°,   final  27°. 

Spec,  gravity  of  brine  at  60°  =  1.1  in  ;  spec,  heat  =  0.8326  ;  weight 
of  1  cb.  ft.  =  69.83  Ibs.;  coal  used  =  3,988  Ibs. 

Actual  refr.  capacity  R  =  P   X   s   X   (t  —  to   -~  284,000. 

P  =  Ibs.  of  brine  circulated  in  24  hrs.  =  660  X  69.83  X  24  = 
1,106,000  Ibs.  ;  t  =  final  temp,  of  brine  =  27 ;  ti  =  initial  temp. 
=  17;  s  =  spec,  heat  of  brine  =  0.8326. 

R  -  1,106,000  X  0.8326  (27  —  17)  -4-  284,000  =  32.3  tons  in  24 
hrs. 

Condensing  water  used  per  minute  =  235  X  7.5  -T-  60  =  29.3 
gallons.  (I  cb.  ft.  =  7.5  gallons.) 

Rules  for  Testing  Refrigerating  Machines. 

(Abridged1  from  Preliminary  Report  to  A.  S.  M.  E.) 
The  unit  to  measure  the  cooling  effect  or  the  refrigeration  is  the 
heat  required  to  melt  1  pound  of  ice,  which  is  144  British  thermal 
units,  and  by  dividing  the  refrigeration  measured  in  British  thermal 
units  by  144,  the  ice  melting  capacity  in  pounds  is  obtained.  The 
unit  for  a  ton  of  2,000  pounds  of  ice  melting  capacity  is  therefore 
288,000  British  thermal  units.  The  tonnage  capacity  is  the  re- 
frigerating capacity  expressed  in  tons  of  ice-melting  capacity  in 
24  hours,  and  is  equivalent  to  the  abstraction  of  288,000  British 
thermal  units  in  24  hours,  or  to  12,000  British  thermal  units  per 
hour,  or  200  British  thermal  units  per  minute. 

The  unit  for  measuring  the  commercial  tonnage  capacity  is 
based  upon  the  actual  weight  of  refrigerating  fluid  circulated  be- 
tween the  condenser  and  the  refrigerator,  and  actually  evaporated 
in  the  refrigerator. 

•The  actual  refrigerating  capacity  of  a  machine  may  be  determined 
from  the  quantity  and  range  of  temperature  of  the  brine,  water, 
or  other  secondary  refrigerating  liquid  circulated  as  a  refrigerant, 
and  the  actual  refrigerating  capacity  under  the  standard  set  of 
conditions  should  correspond  closely  to  the  commercial  tonnage 
capacity. 

The  standard  set  of  conditions  are  those  which  often  exist  in  ice 
making,  namely  that  the  temperature  of  the  saturated  vapor  at  the 
point  of  liquefaction  in  the  condenser  is  90  degrees  F.  and  the 
temperature  of  the  evaporation  of  the  liquid  in  the  refrigerator 
0  degrees  F.  This  corresponds  for  ammonia  to  a  condenser  pres- 
sure of  about  168  pounds  gauge  pressure,  and  to  a  gauge  pressure 
of  about  15  pounds  in  the  refrigerator. 

In  the  case  of  air  machines,  the  actual  tonnage  capacity  for  a 
specified  set  of  conditions  is  obtained  by  basing  the  refrigeration  on 
the  amount  of  air  cooled  and  tae  amount  which  it  is  lowered  in 
temperature. 

In  the  Code  of  Rules  the  primary  refrigerating  fluid  is  consid- 
ered to  be  ammonia,  out  the  rules  will  apply  no  matter  what  the 
refrigerating  fluid  may  be. 

In  a  brine  circulating  system  where  brine  coils  are  made  use  of 
to  produce  the  refrigerating  the  capacity  of  these  coils  is  not  there- 
fore taken   into  account.     A  test  made   with  a  brine  heater  gives 
correctly    the    capacities    herein    specified. 
Calibration  of  Thermometers. 

All  the  thermometers  used  should  be  carefully  calibrated  before 
employing  them  in  a  test.  The  32  degree  point  may  be  determined 
by  noting  their  readings  when  surrounded  by  melting  ice,  and  other 
points  by  comparing  with  a  standard  thermometer  which  should 
also  be  calibrated  at  its  ice  point  in  order  to  make  sure  that  it 
is  correct. 

Thermometers  having  the  graduations  marked  directly  on  the 
glass  stems  should  be  used,  and  these  should  be  placed  in  wells 


EFFICIENCY  TEST  OF  PLANT.  119 

containing  brine  or  mercury,  the  wells  to  extend  for  at  least  2 
Inches  into  the  space  whore  the  fluid  circulates.  The  mercury  in 
the  stem  of  the  thermometer  should  stand  a  little  higher  than,  the 
top  of  the  well,  in  order  that  the  readings  may  'be  obtained  without 
moving  the  thermometer.  Where  the  range  of  temperature  through 
which  the  refrigerating  fluid  is  cooled  is  measured  in  order  to  de- 
termine the  capacity  of  the  machine,  it  is  often  necessary  to 
measure  this  range  with  the  highest  degree  of  refinement.  For  ex- 
ample, if  a  refrigerating  machine  cools  brine  through  a  range  of  5 
degrees,  one-tenth  of  a  degree  will  be  equivalent  to  2  per  cent,  of 
the  range  of  temperature,  and  it  is  therefore  essential  that  the 
range  should  be  determined  wita  as  great  accuracy  as  possible.  In 
general,  it  is  well  to  interchange  the  thermometers  which  are  used 
for  measuring  the  temperatures  of  the  inlet  and  outlet  brine  several 
times  during  a  test,  making  note  of  such  changes  on  the  record  of 
the  test. 

Calibration  of  Water  and  Brine  Meters. 

Where  meters  are  used  for  determining  the  amount  of  refrigerat- 
ing fluid  which  is  circulated  they  should  he  carefully  calibrated, 
both  before  and  after  a  test,  and  in  some  cases,  where  long  tests 
are  made,  they  should  also  be  calibrated  during  the  test. 

In  calibrating  a  meter  the  measurements  should  be  made  with 
the  meter  in  the  position  in  which  it  is  installed  in  the  test.  This 
is  especially  necessary  where  the  liquid  which  is  measured  is  cir- 
culated by  means  of  a  pump  which  produces  pulsations  in  the  pres- 
sure, because  the  pulsations,  as  well  as  the  total  pressure,  must  be 
the  same  in  calibrating  the  meter  as  exist  in  the  actual  test.  In 
calibrating  a  meter  with  either  water  or  brine  the  temperature  of 
the  fluid  should  be  about  the  same  as  exists  in  the  test. 

Duration  of  Test. 

The  duration  of  a  test  depends  upon  its  character.  If  a  test  is 
made  of  an  ice  making  plant,  and  it  is  desired  to  obtain  the 
actual  amount  of  ice  made  per  pound  of  steam  consumed,  it  may 
be  necessary  to  make  tests  of  a  week  or  more  in  duration  in  order 
to  eliminate  as  far  as  possible  any  error  in  estimating  the  amount 
of  ice  and  cold  stored  in  the  freezing  tank,  which  should  be  made 
as  nearly  as  possible  the  same  at  the  end  as  at  the  beginning  of  the 
test. 

Where  the  refrigerating  capacity  is  measured,  the  conditions 
should  be  made  as  nearly  the  same  as  possible  at  the  beginning 
and  the  ending  of  a  test.  By  making  the  test  of  a  long  enough 
duration,  any  error  involved  through  irregularities  will  be  prac- 
tically eliminated  and  in  most  cases  all  tests  should  be  of  at  least 
8  hours  duration. 

It  is  essential  that  the  average  temperature  of  that  part  of  the 
brine  between  the  points  where  its  temperature  is  measured  and 
where  it  is  cooled  by  the  evaporation  of  the  ammonia,  as  well  as 
the  quantity  of  this  part  of  the  brine,  be  the  same  at  the  end  as 
at  the  start  of  the  test.  If  there  is  much  difference  in  tempera- 
ture or  quantity,  a  correction  should  he  applied. 

Conditions  Existing   in,    Tests. 

Where  a  machine  is  guaranteed  to  develop  a  certain  capacity  with 
a  certain  quantity  of  condensing  water  at  a  certain  temperature,  it 
is  often  necessary  to  heat  the  condensing  water  to  the  tempera- 
ture specified  in  the  contract  (circulating  the  water  through  a 
heater  in  which  steam  is  admitted). 

All  conditions  specified  in  a  contract  should  be  followed  as  closely 
as  possible  in  making  a  test. 


I2O 


EFFICIENCY  TEST  OF  PLANT. 


Amount  of  Anvmonia  Circulated  and  Evaporated. 

The  anhydrous  ammonia  must  necessarily  be  measured  under  pres- 
sure. The  best  method  is  actually  to  weigh  it,  employing  two  tanks 
having  flexible  metallic  pipe  connections  for  the  purpose. 

The   arrangement  of  the  two   ammonia   cylinders  for   measuring 


FIG   54— MEASURING    ANHYDROUS   AMMONIA. 

the  anhydrous  ammonia  is  shown  in  diagram.  The  ammonia  re- 
ceiver installed  with  the  machine  is  marked  A,  and  one  of  the  two 
tanks  for  weighing  the  anhydrous  ammonia  B  and  the  other  K. 
In  using  the  tanks  for  weighing  anhydrous  ammonia  the  valve  D 
is  closed.  In  filling  the  tank  R,  the  valves  E  and  F  are  opened 
and  the  valve  G  is  closed.  After  the  tank  B  is  filled,  the  valve  E 
is  closed  and  the  weight  determined,  after  which  the  valve  O  is 
opened,  and  the  anhydrous  ammonia  is  allowed  to  flow  from  the 
tank  through  the  throttle  valve  or  cock  H  into  the  refrigerator. 
During  the  time  that  the  anhydrous  ammonia  is  allowed  to  flow 
from  the  tank  B  through  the  throttle  valve  or  cock  H,  the  second 
tank,  K,  similar  in  construction  'to  5,  which  is  connected  to  the 
pipes  I  and  J,  is  being  filled. 

In  setting  up  the  apparatus,  care  must  be  taken  that  the  hori- 
zontal pipes.  G,  K,  I  and  J  leading  to  the  two  tanks,  are  long 
enough  to  allow  sufficient  flexibility  to  insure  the  proper  working 
of  the  scales.  Care  must  be  taken  also  that  the  pipes  /  and  K 
are  so  connected  that  no  liquid  ammonia  can  enter  them,  while  the 
tanks  for  weighing  the  ammonia  are  being  emptied.  The  liquid 
ammonia  receiver  must  be  large  enough  to  allow  the  level  of  the 
liquid  to  be  carried  at  all  times  well  below  the  inlets  of  the  pipes 
/  and  K.  The  tanks  B  and  K  may  be  covered  with  a  nonconductlve 
covering  to  diminish  the  heating  or  cooling  effect  of  the  atmosphere 
on  them.  There  should  be  little  or  no  tendency  to  evaporate  the 
liquid  ammonia  or  to  condense  the  ammonia  vapor  in  the  tanks  B 
and  ZT,  and  that  such  is  the  case  may  be  determined  by  allowing 
them  to  stand  for  some  time  with  the  vent  pipes  open  to  the  am- 
monia receiver  A,  and  noting  whether  they  gain  or  lose  in  weight. 

Actual  Refrigerating  Capacity. — In  determining  the  actual  re- 
frigerating capacity  of  the  machine  the  conditions  must  be  those 
specified  in  the  contract.  For  example,  if  a  machine  is  guaranteed 
to  produce  a  certain  tonnage  of  refrigeration  in  cooling  a  storehouse 
in  summer  weather,  the  test  should  be  made  in  the  summer,  if 
possible,  or  the  capacity  of  the  coils,  which  are  used  for  refrigerat- 
ing the  various  rooms,  may  be  tested  by  employing  relatively 
warmer  brine.  If  the  heat  given  to  the  brine  is  then  not  sufficient, 


EFFICIENCY  TEST  OF  PLANT.  121 

a  heater  may  be  readily  constructed1  of  a  coil  through  which  the 
brine  passes,  which  is  immersed  in  steam,  so  that  the  required 
amount  of  heat  is  sdded  to  the  brine. 

Specific  Heat  of  Brine  Used. — In  all  cases  where  the  actual  re- 
frigerating effect  is  measured  by  the  cooling  produced  in  the  brine 
circulated,  the  specific  heat  of  the  brine  should  be  determined. 

Temperature  and  Pressure  of  Ammonia  Gas  Leaving  Refrigerating 
Coils. — It  is  necessary  in  computing  the  commercial  refrigerating 
capacity  from  the  weight  of  anhydrous  ammonia  circulated  that 
the  pressure  and  the  temperature  of  the  gas  leaving  the  refrigerator 
be  known.  As  the  pressure  of  the  gas  leaving  the  refrigerator  is 
nearly  that  existing  in  the  refrigerator,  it  may  be  taken  as  such 
without  sensible  error.  Unless  the  gas  leaving  the  refrigerator  is 
superheated,  there  may  be  some  liquid  anhydrous  ammonia  leaving 
the  refrigerator  coils  along  with  the  gas.  A  thermometer  at  this 
point  is  necessary  in  all  tests,  because  if  any  liquid  ammonia  leaves 
the  refrigerator  the  calculated  results  will  be  too  great  and  the 
machine  will  be  doing  less  refrigeration  than  indicated  by  the 
measured  amount  of  ammonia  circulated. 

Temperature  of  A-mw.onia  at  the  Expansion  Valve. — It  Is  neces- 
sary in  computing  the  commercial  tonnage  capacity  that  the  tem- 
perature of  the  anhydrous  ammonia  be  known  on  the  high  pres- 
sure side  of  the  expansion  valve.  A  thermometer  well  should  be 
inserted  in  the  pipe  for  this  purpose. 

Commercial   Tonnage  Capacity. — The   commercial   tonnage   capac- 
ity should  be  computed  from  the  formula  : 
W 

R  = [Iv  —  q  +  cp    «!  —  *)]     (1) 

12,000 

Where  R  =  the  commercial  tonnage  capacity  or  the  tons  of  ice 
melting  capacity  per  24  hours. 

W  =  the  weight  of  anhydrous  ammonia  evaporated  in  the  refrig- 
erating coils  in  pounds  per  hour. 

1/2  =  the  total  heat  above  32  degrees  F.  of  1  pound  of  the 
saturated  ammonia  gas  at  the  pressure  of  the  refrigerator. 

q  —  the  sensible  heat  above  32  degrees  F.  contained  in  1  pound 
of  the  liquid  ammonia  at  the  temperature  observed  before  it  passes 
through  the  expansion  valve. 

cp  =  the  specific  heat  of  ammonia  gas  at  constant  pressure 
of  0.51. 

ti  —  the  temperature  of  the  superheated  ammonia  gas  leaving 
the  refrigerator  in  degrees  F. 

t  =  the  temperature  corresponding  to  the  pressure  at  which  the 
ammonia  gas  leaves  the  refrigerator  in  degrees  F. 

The  specific  heat  of  liquid  anhydrous  ammonia  is  very  nearly 
unity,  and  if  taken  at  this  figure,  we  obtain  (2)  : 

W 

R  = [H2—  (7\  —  T2)     +    op    (*!  —  *)    ]     (2) 

12,000 

Where  H2  =  the  latent  heat  of  evaporation  of  1  pound  of  an- 
hydrous ammonia  at  the  pressure  of  the  refrigerator. 

TI  =  the  temperature  of  anhydrous  ammonia  observed  just  be- 
fore it  passes  through  the  expansion  valve  in  degrees  F. 

T2  —  the  temperature  corresponding  to  the  pressure  of  the  am- 
monia gas  in  the  refrigerator  in  degrees  F.,  and  the  remainder  of 
the  notation  is  the  same  as  in  equation  (1). 

In  determining  the  commercial  tonnage  capacity  it  is  necessary 
to  make  sure  that  the  anhydrous  ammonia  is  pure.  In  the  case  of 
absorption  machines,  there  is  usually  some  water  present  in  the 
ammonia.  The  quantity  of  water  should  be  determined. 


122  EFFICIENCY  TEST  OF  PLANT. 

Actual  Refrigerating   Capacity. — The   actual   refrigerating  capac- 
ity  should  be  computed  from   the  formula  : 
WiC 

Rl    -    -      -    (t2  —  t3)  (3) 

12,000 

Where  RI  =  the  actual  tonnage  capacity,  or  the  tons  of  Ice 
melting  capacity  per  24  hours. 

Wi    =    the   weight   of  refrigerating   fluid   circulated  per  hour. 

o  =  the  specific  heat  of  the  refrigerating  fluid  for  the  range  of 
temperature  existing  in  the  tests. 

t2  =  the  temperature  of  refrigerating  fluid  returned  to  the  ma- 
chine, and1 

ts  —  the  temperature  of  refrigerating  fluid  leaving  the  machine. 

Indicator  Cards,  etc. — Indicator  cards  should  be  taken  from  the 
steam  and  ammonia  cylinders  of  a  compression  machine.  Thermom- 
eter wells  should  be  placed  in  the  inlet  and  exit  ammonia  pipes  of  a 
compressor,  and  the  temperatures  observed. 

Strength  of  Liquors  in  Absorption  Macliine. — The  density  of  the 
strong  and  weak  liquors  should  be  determined  in  testing  an  ab- 
sorption machine.  It  is  essential  in  doing  this  that  no  gas  be 
allowed  to  escape  from  the  liquids  on  drawing  from  the  machine. 
The  liquors  should  be  drawn  off  through  a  pipe  which  is  surrounded 
with  cold  brine  or  some  other  refrigerant,  and  the  density  should 
be  determined  at  a  temperature  at  which  there  is  practically  no 
evaporation. 

Heat  Balance. — A  balance  should  be  made  of  the  various  quan- 
tities of  heat  received,  and  rejected  by  a  machine.  This  Is  Import- 
ant as  proving  the  accuracy  of  a  test.  The  following  table  gives 
the  essential  data  and  results  for  a  test  to  determine  the  com- 
mercial tonnage  capacity  : 

1.  Duration  of  test hours 

2.  Anhydrous  ammonia   evaporated1  per   hour  in   the   refrigerating 

coils    (W) Ibs. 

3.  Average   condenser  pressure  above  atmosphere,  or  gauge,  pres- 

sure  (made  as  near  168  Ibs.  a  square  inch  above  the  atmos- 
phere as  possible)    Ibs.  per  sq.  in. 

4.  Average  refrigerator  pressure  above  atmosphere  or  gauge  pres- 

sure  (made  as  near   15   Ibs.   a  square   inch  above  the  atmos- 
phere  as  possible) Ibs.   per   sq.    in. 

5.  Average  temperature  of  liquid  ammonia  on  high  pressure  side 

of   the   throttling  valve   or   cock    (TO deg.    F 

6.  Average   temperature  of  ammonia  gas   leaving  the   refrigerator 

(ti) deg.    F. 

7.  Temperature   of   saturated   ammonia   gas    corresponding   to   the 

average    refrigerator    pressure    (T2) dfg-    F. 

8.  Total   heat  above   32   degrees  F.   of  1   pound  of  saturated  am- 

monia gas  at  the  average  refrigerator  pressure  (L2)  .  .  .  B.  t.  u. 

9.  Sensible    heat   above    32    degrees   F.    contained    in    1   pound    of 

liquid  ammonia  at  the  temperature  observed*  before  it  passes 
through  the  throttle  valve  or  cock   (q) B.  t.  u. 

10.  Commercial    tonnage    capacity    =    R    as   figured    by    equations 

(1)   and   (2). 


PART   V— THE   STEAM  PLANT 


Steam  Engines 
Horse-Power. 

The  indicated  horse-power  is  found!  by  the  following  formula: 
I.  H.  P.  =  a  s  p  -f-  33,000. 

a  =  piston  area  in  inches  (deduct  area  of  rod). 
s  —  piston  speed  in  ft.  per  min.  =  2   X  stroke  X'  rev.  p.  min. 
p  =  mean  effective  pressure  in  Ibs.  p.  sq.  inch  of  piston. 
The  Actual   or  Brake   Horse-Power  equals   the   indicated   horse- 
power less   the  power   required  to  run   the   engine   itself,   which  Is 
ordinarily  25%  of  the  total  power.     The  ratio  between  the  indicated 
and  brake  horse-power  is  called  Mechanical  Efficiency. 

The  Mean  Effective  Pressure  is  computed  from  an  indicator  dia- 
gram, or  may  be  obtained  approximately  from  table  below. 

MEAN     EFFECTIVE     STEAM     PRESSURE. 


Cut-off  at 

A 

* 

* 

I 

* 

* 

t 

ft 

* 

f 

1 

Apparent  Ratio  of 
Expansion. 

10 

9 

8 

7 

6 

5 

4 

3.33 

3 

2  5 

2 

M   E.P.  perLb. 
Initial  Pressure. 

-.330 

.355 

.385 

.421 

465 

.523 

.596 

.661 

,699 

.770 

.846 

Initial  Pressure. 

Me. 

m  Eff 

>ctive 

Pressur 

:  from  1 

~ull  Ar 

saof  Id 

eal  Diaj 

jram. 

Gauge  |  Absolute. 

40 

54.7 

18  07 

19.42,21.06 

tt.03 

25.44 

28.55 

32.63 

30  15 

33.26 

41.93 

46  31 

45 

59.7 

19  72 

21.19,22.98 

25.12 

27.76 

31.16 

35.62 

39.46 

41  "<6 

45.76 

50.54 

50 

64.7 

21  37 

22.9724.91 

27.23 

30.09 

33.77 

38.60 

42.76 

45.26 

49.59 

54.77 

55 

69.7 

23.02 

24.74 

26.83 

29.34 

32  31 

36.38 

41.58 

46.07 

48.76 

53.43 

59.00 

60 

74.7 

24.67 

<>6  5? 

98  75 

31.45 

34.74 

38.99 

44  56 

49.37 

52  26 

57.26 

63.24 

65 

79  7 

26.32 

*8  «0 

30.68 

W  55 

37  06 

41.59 

47.55 

52  67 

55.75 

61.09 

67.47 

70 

84.7 

>7  97 

30  07 

3?,  60 

15,66 

39.39 

44.20 

50.53 

55.98 

59.85 

64.92 

71.70 

75 

89.7 

29.62 

31.84 

34.53 

37  76 

41.71 

46.81 

53.51 

59.28 

62  75 

68.76 

75.94 

80 

94.7 

31.28 

33.62 

36.45 

19  87 

44.04 

49.42 

56.50 

62.59 

66.25 

72.59 

80.17 

85 

99.7 

32.93 

35.39 

W  38 

41  91 

46.36 

52.03 

59.  4S 

65.89 

66.74 

76.42 

84.40 

90 
95 

104.7 
109.7 

34.5837.17 
36.2338.94 

40.30 
42.23 

44.08 
46.18 

48.69 
51.01 

54.64 
57.25 

62.46 
65.44 

69.20 
72.50 

73.24 
76.74 

80.26 
84.09 

88.63 
92.87 

100 

114.7 

37  88 

40.72 

44.15 

48  ?0 

53.34 

59.86 

68.43 

75.81 

80.24 

87.92 

97.10 

110 

124.7 

41.18 

44  37 

48  00 

53  50 

57.98 

65.08 

74.39 

82.41 

87.23 

95.59 

105.26 

120 

134.7 

44.49|47.82 

51  85 

56.71 

62.64 

70.30 

80.36 

89.02 

94.23 

103.25 

114.04 

130 

144.7 

47.7951.37 

33.70 

00.92 

67.29 

75.52 

86.32 

95.63 

101.22110.91 

122.50 

140- 

154.7 

51.0954.92 

59.55 

65  13 

71.94 

80.74 

93.29 

102.24 

108.22 

118.58 

130.96 

150 

164.7 

54.39iJ8.47 

63,40 

69.34 

76.59 

85.96 

98.26108.85 

115  21 

126.26 

139.43 

160 
170 

174.7 
184  7 

57.70 
61.00 

61.02 
65.57 

67.25 
71.10 

73.55 
77.76 

81.24 
85.89 

91.17 
96  39 

104.  221115.  46 
110.19122  07 

122.21 
129.20 

133.91 
141  90 

147.89 
156.36 

180 

194.7 

64  80 

fl9.1? 

74.95 

81,97 

90.54 

101.61 

116.15128.68 

136  20 

149.24 

164.83 

190 

204.7    67  60 

72.67 

78.  79186.18 

95.19 

106.83 

122.12  135.29 

143.19 

156.91 

173.29 

200 

214.7     70.91 

76.22 

82.6490.39 

99.84|112  05 

128.08141.90 

150.19 

164.57 

181.85 

210 

224.7     74.2! 

79  78 

86.4994.60:104.491117.27 

134  05  148.51 

157.19 

172.24 

190.22 

1 

1 

1 

To  find  the  highest  M.  E.  P.  realized  in  practice,  subtract  from  the  ideal  values  given  in 
table,  7  Ibs.  for  condensing  engines,  and  20  Ibs.  in  the  case  of  non-condensing  engines. 

The  ideal  M.  E.  P.  for  any  initial  gauge  pressure  not  given  in  table  is  found  by  multi- 
plying your  absolute  pressure  by  the  M.  E.  P.  per  pound  of  initial,  as  given  in  third  line 
of  table. 


124 


STEAM  ENGINES. 


PISTON    SPEED    IN   FEET   PER   MINUTE. 
Ordinary  direct-acting  pumping  engines  (non-rotative)       90  to      130 

Ordinary  horizontal   engines 200  to      400 

Horiz.  comp.  and  triple-expans.  mill  engines 400  to      800 

Ordinary    marine    engines 400  to      650 

Engines  for  large  high-speed  steamships 700  to      900 

Locomotive    engines    (express) 800  to  1,000 

Engines  for  torpedo-boats 1,000  to  1,200 

STEAM  PER    HORSE-POWER   PER   HOUR. 

Plain  slide  valve   engine 60  to  70  Ibs. 

High  speed  automatic  engine 30  to  50  Ibs. 

Corliss  simple  non-cond 25  to  28  Ibs. 

Corliss    comp.    non-cond 23  to  26  Ibs. 

Corliss   simple   condensing 19  to  21  Ibs. 

Corliss  comp.  condensing 13  to  15  Ibs. 

Valve  Setting  of  Corliss  Engine. 

The  following  instructions  are  given  by  the  Frick  Co.  and  apply 
to  all  Corliss  engines: 


Fig.  2 


Fig.  3 

STEAM  VALVE 

FIG  56— VALVE  SETTING  OF  CORLISS  ENGINE. 


The  Steam  and  Exhaust  Valves. — Take  off  the  back  valve  chest 
cover  and  upon  the  bore  of  the  seats  you  will  find  a  mark  which 
coincides  with  the  closing  edge  of  the  port.  (See  Figs.  3  and  4.) 
Look  upon  the  end  of  the  valve  and  find  a  mark  running  towards 
the  center  of  valve;  this  line  coincides  with  the  closing  edge  of 
valve.  Note  that  in  case  of  the  exhaust  valve  the  valve  controls 
the  part  leading  Into  the  exhaust  passage  and  not  the  opening 
from  the  cylinder  downward.  The  upper  edge  of  the  exhaust 
port  Is  the  closing  edge,  and  the  outer  edges  of  the  steam  ports 
are  the  closing  edges. 

The  Wrist  Plate. — You  will  find  a  mark  upon  the  hub  and  cor- 
responding marks  upon  the  hub  of  the  wrist  plate,  when  It  i§ 


STEAM  ENGINES.  125 

moved  back  and  forth  by  the  eccentric.     The  wrist  plate  should 
be  located  exactly  central  between  the  four  valves. 

To  test  the  marks  on  wrist  plate  hub  connect  the  eccentric 
rods  and  engage  or  drop  the  carrier  rod  upon  the  wrist  plate 
stud;  then  rotate  the  eccentric  upon  the  shaft  the  full  extent 
of  its  throw  or  movement  each  way,  and  observe  if  the  marks 
upon  the  hub  of  wrist  plate  at  full  throw  agree  with  the  marks 
upon  the  bracket;  if  not,  disconnect  the  box  trap  of  eccentric 
rod  at  carrier  arm  and  adjust  the  screw  on  stub  end  by  lengthen- 
ing or  shortening  (as  required),  until  the  marks  do  agree  on  both 
extremes  of  movement. 

To  Set  the  Valves. — Place  the  wrist  plate  in  a  vertical  position 
(at  the  central  mark);  turn  the  valves  around  in  their  seats  until 
the  steam  valves  show  by  the  closing  edge  marks  upon  their 
ends  by  comparison  with  the  port  line  marks  in  the  seats  that  the 
steam  valve  edges  lap  over  or  cover  the  ports  %  of  an  inch  for 
18-inch  T)ore  of  engine  cylinder,  %  for  24-inch  cylinder,  and 
7/16  for  80-inch  cylinder.  The  exhaust  valves  should  show  from 
1/16  to  y&  opening,  according  to  size  of  cylinder. 

In  connecting  the  wrist  plate  see  first  that  the  cut-off  latch  is 
hooked  on  the  stud  or  is  engaged.  Connect  the  wrist  plate  and 
steam  and  exhaust  valve  arms  so  the  wrist  plate  stands  at  the 
central  mark  or  vertical,  and  the  steam  and  exhaust  valve  have 
the  proper  lap  and  opening  as  instructed,  the  proper  amount  of 
steam  lap  and  exhaust  opening  being  determined  as  above  by  the 
size  of  engine. 

To  Make  Final  Adjustments. — Now  with  the  carrier  rod  hooked 
upon  the  wrist  plate  stud,  place  the  engine  upon  the  center,  know- 
ing which  way  the  engine  shaft  is  to  run,  turn  the  eccentric 
upon  the  shaft  (it  being  loose)  in  the  same  direction  in  which 
shaft  is  run,  a  little  more  than  at  right  angles  ahead  of  the 
crank  or  until  the  steam  valve  on  the  same  end  as  the  piston  Is 
just  beginning  to  open,  say  1/32  of  an  inch;  in  this  position  secure 
the  eccentric  on  the  shaft  by  means  of  the  set  screws  in  the  hub 
(see  in  all  cases  that  the  steam  valves  are  hooked  up  or  engaged 
t)y  the  cut-off  mechanism),  then  turn  the  engine  on  the  opposite 
center  and  see  if  the  steam  valve  on  that  end  has  the  same 
amount  of  opening;  if  not,  you  can  make  the  adjustment  by 
lengthening  or  shortening  the  wrist  plate  rod  attached  to  this 
valve. 

To  Adjust  the  Cut-off. — See  that  the  governor  and  connections 
are  put  together  properly,  and  block  the  governor  about  halfway 
in  the  slot ;  then  fasten  the  reach  or  cam  rod  lever  so  it  stands 
about  at  right  angles  to  a  line  drawn  midway  between  the  reach 
rods;  then  lengthen  or  shorten  the  reach  rods  until  the  cam  or 
trip  levers  stand  vertical  or  plumb.  The  governor  and  connections 
now  occupy  the  proper  relative  positions,  and  it  remains  to 
make  the  exact  adjustment  and  to  equalize  the  cut-off,  so  as  the 
same  amount  of  steam  is  admitted  at  each  end  of  the  stroke. 
Also,  lower  the  governor  and  observe  when  the  governor  is  down 
that  the  cut-off  mechanism  does  not  unhook,  but  allows  steam 
to  be  taken  full  stroke,  after  which  place  the  engine  at  1-5  of  the 
stroke,  which  can  be  done  by  measuring  upon  the  engine  bed 
guides  from  each  end1  and  turning  the  engine  (with  all  parts 
connected  up)  until  crosshead  is  fair  -with  the  mark,  then  slowly 
raise  the  governor  until  the  cut-off  on  the  end  taking  steam 
trips  or  unhooks,  and  to  ensure  this  point  being  accurately  de- 
termined it  is  well  to  stand  by  with  the  hand  pressing  down 
upon  the  dash  pot  rod;  now  block  the  governor  in  this  position 
;md  try  the  cut-off  on  the  other  stroke  same  distance  from  the 
end.  After  a  few  trials  back  and  forth,  and  adjusting  the  length 
of  the  cam  rods,  the  cut-off  can  be  made  to  drop  at  precisely  the 


126 


STEAM  ENGINES. 


same  point  of  stroke.  Take  care  to  secure  everything  perma- 
nently when  done. 

Note :  on  Automatic  Safety  Attachment. — As  most  engines  are 
fitted  with  safety  automatic  cams,  designed  to  act  only  when 
governor  has  fallen  to  bottom  of  slot  in  the  governor  column, 
before  finishing  your  adjustment  see  that  when  the  governor  is 
at  its  proper  height  it  will  trip  the  cut-off.  When  resting  on 
the  high  part  of  the  slotted  safety  collar,  the  valve  gear  will 
follow  full  stroke,  and  when  safety  collar  has  been  turned  to 
bring  the  notch  opposite  slot,  the  governor  will  drop  low  enough 
to  allow  the  safety  cams  or  knock-off  lever  to  be  brought  into 
play  so  as  not  to  permit  the  valves  to  be  opened. 

The  dash  pot  rod  should!  be  adjusted  in  length  so  the  steam 
valve  arm,  resting  thereon,  when  the  dash-pot  plunger  is  home,  or 
at  the  bottom  of  the  pot,  is  in  such  a  position  that  the  latch  is 
sure  to  hook  over  the  latch  stud  and  the  stud  lies  midway  between 
the  latch  die  and  the  closing  shoulder.  This  will  insure  on  the 
one  hand  the  positive  engagement  of  the  latch,  and  on  the  other 
hand  prevent  the  shoulder  from  jamming  down  upon  the  latch 
atud.  If  the  dash-pot  rod  is  too  short,  the  latch  will  not  hook  on. 

The  regular  gag  pot  is  used  on  Corliss  Engines  to  prevent  over- 
sensitiveness  of  the  governor  and  its  response  to  trivial  changes. 
Use  only  coal  or  kerosene  oil  in  this  pot,  and  regulate  the  screw 
In  the  piston  if  required  to  give  greater  freedom  of  motion. 
See  that  all  parts  of  the  governor  move  freely. 

If  the  latch  dies  have  a  tendency  to  slip,  the  latch  spring  may 
be  at  fault.  It  can  be  made  stronger  by  twisting  the  spring 
stud,  bringing  more  tension  against  the  latch.  If  the  stoppage 
comes  from  wear,  take  out  the  latch  or  stud  die  and  turn  it, 
thus  presenting  a  new  wearing  surface,  or  sharpen  edge  by  ap- 
plying to  a  grindstone.  Do  not  bring  any  more  pressure  on  the 
spring  than  necessary,  as  when  steel  dies  are  in  good  condition 
the  tension  of  spring  can  be  very  light.  Keep  the  cushion  leathers 
in  good  order  and  your  valve  gear  working  noiseless  and  smooth. 

Using  a  Steam  Engine  Indicator 

to  test  the  correctness  of  valve  setting  is  the  most  approved 
method  known,  and  should  be  applied  in  cases  where  an  indicator 
can  be  obtained.  Recollect  that  to  adjust  the  point  of  cut-off 


\Cross-pipe  connection. 
FIG   57. 


Indicator  and  reducing-wheeL 
PIG   58. 


to  take  same  amount  of  steam  at  each  end,  adjust  the  cam  or 
reach  rods.  To  give  more  or  less  steam  lead  adjust  the  wrist 
plate  rods.  Lengthening  them  increases  the  lap  and  shortening 
them  gives  more  lead.  The  same  with  the  exhaust  valves,  the 
cushion  or  release  being  effected  thereby.  If  the  eccentric  is 
properly  set,  it  is  not  necessary  to  disturb  it  in  ordinary  cases. 


STEAM  ENGINES. 


127 


FIG    59. 


The  lines  of  a  perfect  diagram  are 
as  follows: 

A  to  B  is  the  "admission  line," 
showing  that  ports  and  clear- 
ance space  are  filled  with  steam. 

B  to  C  is  the  "steam  line/'  show- 
ing that  sufficient  steam  is  ad- 
mitted to  the  cylinder  up  to  the 
point  of  cut-off  at  C. 

C  to  D  is  the  "expansion  line/' 
showing  the  work  done  by  the 
expansion  of  the  steam  while 
piston  travels  from  point  of  cut- 
off to  point  of  release  at  D. 

D  to  B  is  the  "release  line/' 
where  the  exhaust  valve  opening 
lets  the  steam  escape  from  the 
cylinder. 

E  to  F  is  the  tack  pressure  line, 
showing  the  amount  of  pressure 
on  the  back  of  the  piston. 

At  P  occurs  the  exhaust  closure, 
and  P  to  A  is  the  coompression 
line,  showing  how  the  pressure 
is  raised. 

ADMISSION   LINE. 

a.  Normal,    b.  Not  sufficient  lead. 

c.  Not  sufficient  lead  (slide  valve). 

d.  Steam  admitted  too  late. 

e.  Exhaust  valve  closing  too  late, 
f  and  g.   Too  much  compression  for 

late  steam   opening, 
h    and    i.     Too   much    compression 

(slide  valve), 
j  and  k.    Too  much  lead. 
STEAM   LINE, 
a.  Normal,  b.  Steam  ports  or  steam 

pipe   too   small. 

c.  Too  large  steam  chest  area. 

d.  No  load  on  engine. 

e.  Piston    speed    too    great    (slide 
valve). 

POINT   OF   RELEASE, 
a.  Normal,     b.  Release  too  late. 

c.  Counterpressure    at    moment    of 
normal  release. 

d.  Release  too  early. 

e.  Release  too  late  (condensing), 
f  and  h.   Light  load  or  early  cut-off, 
g.  Late  cut-off. 

BACK  PRESSURE   LINE, 
a.  Normal,  b,  c  and!  d.    Insufficient 
exhaust  area. 

e.  Small  exhaust  ports. 

f.  Continuous    diagram    with    vary- 
ing load. 

g.  Early  closure  of  valve. 

COMPRESSION  LINE, 
a.  Normal,    b.  Excess,  compression, 
c  and  d.     Leakage  in  valves  or  pis- 
ton, 
e.  Leakage  in  piston. 


128 


STEAM  ENGINES. 


Taking  Care  of  Corliss  Engine. 

Before  starting  your  engine,  see  that  all  the  water  is  blown 
out  of  the  steam  pipe  by  means  of  the  drip  valve  provided  on 
steam  valve  elbow;  then  open  the  steam  valve  a  little  and  allow 
the  steam  to  blow  through  the  cylinder,  first  one  end,  then  the 
other,  by  moving  the  wrist  plate  by  hand  sufficient  to  let  the 
steam  pass  through  the  valves.  The  cylinder  soon  becomes  warm, 
and  all  water  is  expelled  into  the  exhaust  pipe,  the  exhaust  drain 
cock  having  been  left  open  to  allow  it  to  run  off.  When  ready 
to  start,  let  the  engine  move  slowly  until  you  are  satisfied  every- 
thing is  all  right,  then  open  stop-valve  wide,  and  leave  same 
open  at  all  times. 

Don't  work  the  wrist  plate  motion  by  hand  and  run  engine 
backward  and  forward;  the  carrier  rod  is  provided  with  a  de- 
tachable hook  so  wrist  plate  may  be  worked  for  the  purpose  of 
warming  up  steam  cylinder  and  blowing  through. 

When  machine  is  stopped,  wipe  it  down  clean,  and  examine  all 
bearings  and  parts.  Before  starting  again,  see  that  all  oil  cups 
are  properly  filled  and  in  working  order,  and  all  oil  holes  clear. 
Use  none  but  the  best  oil,  and  use  no  more  of  it  than  is  required 
to  keep  bearings  in  good  working  condition. 

Air  Pumps. 

For  a  jet-condensing  engine  the  capacity  of  the  vertical  single- 
acting  pump  varies  from  1/5  to  1/10  of  the  capacity  of  the  low- 
pressure  cylinder,  and  from  1/8  to  1/16  in  case  of  a  horizontal 
double-acting  pump. 

For  a  surface-condensing  engine  the  capacity  of  the  s.  a.  pump 
would1  be  from  1/10  to  1/8,  and  of  a  d.  a.  pump  1/15  to  1/25  of 
that  of  the  low-pressure  cylinder. 

The  above  proportions  are  for  pumps  having  the  same  number 
of  strokes  as  the  piston  of  the  low-pressure  cylinder. 


PIG  60— SURFACE  CONDENSER  WITH  AIR  AND  CIRCULATING  PUMP. 


STEAM  ENGINES. 


129 


o.     5 

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SSS3?JS?;3SiSSSSSS^??^ 


Steam  Boilers 

Horse  Power. 

The  standard  rating  is  as  follows  :  One  horse-power  equals  30 
Its.  of  water  evaporated  p.  hr.f  from  feed  water,  at  100°  F.  into 
dry  steam  of  70  Ibs.  gauge  pressure. 


'     Internal  fired,  cylindrical  tub-  j 
ular  boiler. 


-Sterling  water-tube  boder.  'BABCOCK  &  W.  LCOX  WATEK-TUBI  BOILER 

FIG  61— VARIOUS  TYPES  OF  STEAM   BOILERS. 


This  is  equivalent  to  the  evaporation  of  34.5  Ibs.  of  water  from 
a  feed  water  temp,  of  212°  F.  into  dry  steam  at  the  same  temp, 
and  under  atm.  press. 


STEAM  BOILERS. 


APPROXIMATE  PROPORTION  OP  HEATING-SURFACE  AND  GRATE-SURFACI* 
PER  HORSE-POWER,  ETC.,  OF  VARIOUS  TYPES  OF"  BOILERS. 


Coal 

1 

TYP«  or  BOILER. 

Square  feet 
of  heating- 
surface  per 

per 

foot  of 
heat- 

Rela- 
tive 
econ- 

Rela- 
tive 
rapid- 
ity of 

Heating- 
surface  per 
square  foot 

Pounds  of 
coal  per 
square  foot 

Pounds  of] 
water  perl 
pound    i 

horse-power. 

ing- 

omy. 

steam- 

of grate. 

of  grate. 

of  owl. 

sur- 

ing. 

I 

face. 

\ 

Water-tube  

10  to  12 

.3 

1.00 

1.00 

35  to  50 

12  to  20 

9  to  10 

Cylind'l  tubular. 

14        16 

.25 

..91 

.60 

25       35 

10       15 

8  :"'  11  » 

Vertical  tube  

15       20 

.25 

.80 

.60 

25       30 

10       15 

8  "  10| 

Locomotive  

12       16 

.275 

.85 

.55 

50       100 

20       40 

8  "  llj 

Flue  

5       12 

.4 

.79 

.25 

20       25 

10       20 

8  "  10 

Plain  cylindrical  . 

6       10 

.5 

.69 

.20 

15       20 

15       25 

7  "  P 

Mortzortt-ol      Yubutar      Boi 


Ice 


No     H.P. 


FirtMTCf      T*t»l 


75 

90 

too-i 

ISO 

200*> 


2-i 
4-S 

/(? 
/5" 
20 
2S- 

30 

•40 
SO 
60 
73 

90 

/OO 
/2.O 


60 


24 

48 

52 

66 
66 

Iff 

/32 
/02 
/32 


/32 


7670 
&77O 


3S400 


to  ooo 
'ifoo 


ZOooo 


26800 


24000 
.14000 
3BOOO 


.T3000 
56000 


4-00/ 
500 

600 
700 
750 

doo 

/OOO 
//OO 

/3oo 

2OOO 

2200 
Z600 

3000 

3300 


60 


221 »  92*  103 
.118 

"•    Art 


eacK  boiler  to  k«  Urn\*ht4    wi«\  inoLependtnt  shack. 
«n  all  e**e»  <V  *v«tt  boiler  iKaw  ajxti-f  ie4. 

Fuel. 

The  value  of  fuel  is  measured  by  the  number  of  heat  units 
which  its  combustion  will  generate.  The  fuel  is  composed  of 
carbon  and  hydrogen,  and  ash,  with  sometimes  small  quantities 
of  other  substances  not  materially  affecting  its  value. 

"Combustible"  is  that  portion  which  will  burn;  the  ash  or 
residue  varying  from  2  to  36  per  cent,  in  different  fuels. 

"Slack"  or  the  screenings  from  coal,  when  properly  mixed — 
anthracite  and  bituminous— and  burned  by  means  of  a  blower  is- 
nearly  equal  in  value  of  combustible  to  coal,  but  its  percentage  of 
refuse  is  greater. 

Petroleum  has  a  heating  capacity,  when  fully  burned,  equal 
to  from  21,000  to  22,000  B.  T.  TJ.  per  pound,  or  say  50  per  cent, 
more  than  coal.  But  owing  to  the  ability  to  burn  it  with  less- 
losses,  it  has  been  found  that  it  is  equal  to  1.8  pounds  of  coal. 
A  gallon  of  petroleum  is  equivalent  to  twelve  pounds  of  coal, 
and  190  gallons  are  equal  to  a  gross  ton  of  coal.  It  is  very  easy 
with  these  data  to  determine  the  relative  cost. 

It  has  been  estimated  that  on  an  average  one  pound  of  coal  is 
equal,  for  steam-making  purposes,  to  2  Ibs.  dry  peat,  2%  to  2% 
Ibs.  dry  wood,  2-.y2  to  3  Ibs.  dried  tanbark,  2%  to  3  Ibs.  sun- 
dried  bagasse,  2%  to  3  Ibs.  cotton  stalks,  3%  to  3%  Ibs.  wheat 
or  barley  straw,  5  to  6  Ibs.  wet  bagasse,  and  6  to  8  pounds  wet 
tan-bark. 

Natural  gas  varies  in  quality,  but  is  usually  worth  2  to  2% 
times  the  same  weight  of  coal,  or  about  30,000  cubic  feet  are 
equal  to  a  ton  of  coal. 


132 


STEAM  BOILERS. 


TABLE  OF  COMBUSTIBLES. 


m. 

1  Charcoal. 
Carbon  \  Coke, 

|  Anthracite  Coal, 
Coal  —  Cumberland 
"      Coking  Bituminous... 


ing  B 

Cannel 

"       Lignite... 
Peat-Kiln  dri5d 


Air  dried  25  per  cent,  water. . 

Wood— Kiln  dried 

Air  dried  20  percent,  water. 


AMERICAN  COALS. 


j 

Theoretical  Value. 

M 

Theoretical  Value 

COAL. 

M 

in  Heat 
Units. 

Pounds 
of  water 

COAL. 

j!l 

n  Heat 
Units. 

Pounds 
of  water 

STATE.    KIND  OF  COAL. 

£o 

evap. 

STATE.  KIND  OF  COAL. 

P.'o 

evap. 

Penn.  Anthracite  .... 

3-49 

14.199 

14.70 

111.     Bureau  Co  

5.20 

3,025 

3.48 

'•              **           .... 

13.535 

"       Mercer  Co...... 

5.60 

3.123 

3-53 

il                             U 

2.90 

14,22  < 

14.72 

"        Montauk  

5-5° 

2,659 

3.IO- 

"       Cannel  

3.M3 

13-60 

Ind.  Block  

2.50 

3.588 

4-38 

Connellsville.. 

6  50 

3,368 

13-84 

"      Caking  

5-66 

4146 

Semi-bit'nous.. 

10.70 

3.155 

13.62 

"      Cannel  

6.00 

3,097 

,   eg 

"       Stone's  Gas  .. 

5.00 

4,021 

Md.  Cumberland.... 

'13.88 

2.226 

2.65 

Youghiogheny 
**       Brown  

5.60 
9.50 

4.265 
2,324 

i*'76 
12.75 

Ark.  Lignite  
Col.      ^       

5.00 
9.25 

13^562 

9-54 
4.04 

Kentucky  Caking.... 

2-75 

4.39' 

14-89 

4.50 

13,866 

4-35 

||           Cannel.... 

16.76 

Texas    "       

4-5° 

12,962 

3.41 

Lignite  

7.00 

9.326 

13-84 

9-65. 

Wash.  Ter.  Lignite.. 
Penn.  Petroleum.... 

3-40 

11.551 
20,746 

..96 

1-47 

SIZES  OF  CHIMNEYS  WITH  APPROPRIATE  HORSE-POWER   BOILERS. 


HEIGHT  OF  CHIMNEYS. 

V        «: 

.j 

—  ITS  — 

*f 

5oftJ6oft|7oft|8oft. 

90  ft  |iooft.|noft. 

.25  ft- 

150  ft. 

'75  ft. 

200  ft. 

f  is 

"<  3 

1  §  J  si 

C.S 

Commercial  Horse-Power. 

S<| 

<     o- 

53  3_I 

18 

*3 

H 

=  7 
4' 

1 

0.97 
1.47 

2-41 

16 
'9 

34 

49 

54 

62 

2.08 

3.14 

21 

37 

65 

72 

78 

83 

2.78 

3-98 

24 

30 

84 

92 

00 

107 

"3 

3.58 

4-91 

27 

33 

'"5 

25 

'33 

141 

4-47 

5-94 

3° 

36 

141 

52 

'63 

'73 

182 

5  47 

7.07 

32 

39 
42 

1 

196 
231 

208 

$ 

271 

657 
7.76 

8.30 
9.62 

11 

48 

3" 

33° 

348 

365 

389 

10.44 

12.57 

43 

54 

363 

427 

449 

472 

55  ! 

13.51 

15.90 

48 

60 

5°5 

565 

593 

632 

692 

748 

16.98 

19.64 

54 

66 

658 

694 

728 

776 

849 

918 

98l 

20.83 

23.76 

59 

7* 

793 

835 

876 

934 

1105 

25.08 

28.27 

64 

84 

995 
1163 

1038 
1214 

1794 

418 

1531 

'637 

34.76 

38.48 

7° 
75 

90 

^ 

'344 

1415 

1496 

639 

1770 

1893 

40.19 

44-18 

80 

96 

1 

"537 

1616 

876 

2l67 

46  01 

50  27 

86 

Water  for  Feeding  Boilers. 

should  be  soft,  and  deposit  no  sediment  in  the  boiler.  When  it  con- 
tains a  large  amount  of  scale-forming  material  it  is  usually  ad- 
visable to  purify  it  before  allowing  it  to  enter  the  boiler,  instead1 
of  attempting  the  prevention  of  scale  by  the  introduction  of  chem- 
icals into  the  boiler. 

Carbonates  of  lime  and  magnesia  may  be  removed  to  a  consider- 


STEAM  BOILERS. 


133 


able  extent  by  simply  heating  the  water  in  an  exhaust-steam  feed 
water  heater  or  still  better  by  a  live-steam  heater. 

When  the  water  is  very  bad,  it  is  best  treated  with  chemicals — 
lime,  soda-ash,  caustic  soda,  etc. 

TREATMENT   OF    BOILER   PEED   WATER. 


Cause  of  trouble. 

Incrustation. 

Treatment  of  water. 

Carbonate  of  lime  

Soft  scale  

Slaked  lime,  sal-soda. 

Sulphate  of  lime.  

Hard  scale  

Sal-soda,  caustic  soda. 
Slaked  lime  and  sal-soda. 

Corrosion 

Sal-soda,  or  caustic  soda. 

Sediment  of  sand,  clay,  and  mud  | 

Precipitation, 
or  soft  scale  . 
Foaming    and 

\  Alum,  and  filter. 
Slaked  lime,  sal-soda,  or  caustic 

corrosion  
Foaming  ....-< 

soda. 
Frequent  blowing  off  from  boiler, 
or  neutralize  with  hydrochloric 

Corrosion  .  .  . 

acid. 
Slaked  lime,  sal-soda. 

Feed  Water  Heaters. 


Cookson  heater,  purifier 
and  oil-separator. 


Hoppes  feed-water  beater. 


FIG  62— VARIOUS  TYPES  OF   FEED  WATER  HEATERS. 


134 


STEAM  BOILERS. 


PERCENTAGE  OF  SAVING  IN  FUEL  BY  HEATING  FEED- WATER. 
AT  70  POUXDS  GAUGE-PRESSURE. 


STEAM 


ft 

I 

TEMPERATURE  TO  WH 

ca  FEED  is  HEATED. 

i           , 

is 

100° 

110° 

120° 

130° 

140° 

150° 

160° 

170° 

180°    190°    200° 

210° 

220° 

250° 

300° 

3SB 

5.53 

6  38 

7.24 

8.09 

8.95 

9.89 

10.66 

11.52 

' 
12.3813.24  14.09 

14.95 

15.81 

19.40 

29.34 

40° 

5  12 

5  97 

fi  84 

7  69 

8  66 

9  42 

10.28 

11.14 

12.00jl2.87  13.73 

14.53 

15.45J18.89 

28  78 

45° 

4.71 

5.57 

6  44 

7,30 

8,16 

9  03 

9.90 

10.76 

11.62:12.49  13.36 

14.22 

15.09I18.37 

2S.22 

50^ 
55° 
60° 

1$ 
3.47 

5.16 
4.75 
4.34 

t:% 

5.21 

6.89 
6.49 
6.08 

7.76 
7.37 
6.96 

8.64 
8.24 
7.84 

9.51 

10.  38  11.  24:i2.11  '12.  98 
9.  99J10.  85,11.  73:12.60 
9.6010.47ill.34  12.22 

13.85 
13.48 
13.10 

14.72,17  87j27.67 
14.35-|17.38'27  12 
13.98:16.86126.56 

65«    3.05 

3.92 

4.80 

.67 

6.56 

7.44 

8.32 

10.08  10.96  11.84 

12.72 

13.60 

16.35 

26.02 

70°   12.62 

3..  SO 

4.38 

.26 

6.15 

7  03 

7.92 

8  80 

9.68  10.57.11.45 

12.34 

13.22  15.84:25.47 

75°  J2.19 

3.07 

3.96 

.84 

5.73 

6.62 

7.51 

8  40 

9.2810.17:11  06 

11  95 

12.84.15.33  24.92 

80°    1.76 

2.65 

3.54 

.42- 

5.32 

6.21 

7.11 

8.00 

8.8      9.78!l0.67 

11.57 

12.46;14.81  24.37 

85°    1.30 

2.22 

3.11 

.00 

4.90 

5.80 

6.70 

7  59 

8.48    9.38:10.28 

11.18 

12.07  14.32  23.82 

90°    0.89  1.78 
-^5°    0.45  1.34 

2.68 
2.25 

'15 

4.48 
4.05 

5.38 
4.96 

6.  28 
5  86 

7.18 

8.07    8.98!  9.88 
7.66    8.57'  9.47 

10.78 
10.38 

11.68 
11.29 

13.82 
13.31 

23.27 
22.73 

100°    0.00  0.90 

1.81 

2.71 

3.62 

4.53 

5.44 

«.35 

7.25    8.16|  9.07 

9.98 

10.88 

12.80  22.18 

Steam. 

"Saturated  Steam"  is  steam  of  the  temperature  due  to  Its  pres- 

BUre not  superheated.  "Superheated  Steam"  is  steam  heated  to 

a  temperature  above  that  due  to  its  pressure. 

"Dry  Steam"  is  steam  which  contains  no  moisture.  It  may  be 
either  saturated  or  superheated. 

"Wet  Steam"  is  steam  containing  intermingled  moisture,  mist 
or  spray.  It  has  the  same  temperature  as  dry  saturated  steam  of 
the  same  pressure. 

Flow  of  Steam  in  Pipes. 

The  flow  of  steam  through  pipes  la  calculated  after  the  following 
formula :  


W  =  weight  of  steam  in  Ibs.,  which  will  flow  per  minute  through 
a  pipe  of  the  length  L  in  feet  and  the  diameter  d  in  inches ;  PI  =s 
initial  pressure ;  Pa  =  pressure  at  end  of  pipe ;  D  =  weight  per 
cubic  foot  of  the  steam. 

Steam  at  atmospheric  pressure  flows  into  a  vacuum  at  the  ratt 
of  about  1,550  feet  per  second,  and  flows  into  the  atmosphere  at 
the  rate  of  650  feet  per  second. 

Heating  ty  Steam 

One  square  foot  radiating  surface,  with  steam  at  212°,  will  heat 
100  cubic  feet  of  air  per  hour  from  zero  to  150°,  or  300  cubic 
feet  from  zero  to  100°  in  the  same  time. 

Where  the  condensed  water  is  returned  to  the  boiler,  or  where 
low  pressure  of  steam  is  used,  the  diameter  of  mains  leading  from 
the  boiler  to  the  radiating  surface  should  be  equal,  in  inches,  to 
one-tenth  the  square  root  of  the  radiating  surface,  mains  included, 
in  square  feet.  Thus  a  1-inch  pipe  will  supply  100  square  feet  of 
surface,  itself  included.  Return  pipes  should  be  at  least  %  inch  in 
diameter,  and  never  less  than  one-half  the  diameter  of  the  main- 
longer  returns  requiring  larger  pipe. 

One  square  foot  of  boiler  surface  will  supply  from  7  to  10 
square  feet  of  radiating  surface.  Small  boilers  for  house  use 
should  be  much  larger  proportionately  than  large  plants.  Each 
horse-power  of  boiler  will  supply  from  240  to  360  feet  of  1-inch 
steam  pipe,  or  80  to  120  square  feet  of  radiating  surface. 


STEAM  BOILERS. 


135 


Under  ordinary  conditions  one   horse-power   will   heat,   approxi- 
mately, in 

Brick  dwellings,  in  blocks,  as  in  cities....  15,000  to  20,000  cub    ft 

' 


v  '         to  15'°°0  cub  ft. 

Brick  dwellings,  exposed  all  round  ........  10,000  to  15,000  cub.  ft 

Brick  mills,   shops,  factories,  etc  .........     7,000  to  10,000  cub  ft 

Wooden    dwelling,    exposed  ...............     7,000  to  10,000  cub.  ft' 

Foundries  and  wooden  shops  .............     6,000  to  10,000  cub.  ft. 

Exhibition  buildings,  largely  glass,  etc...     4,000  to  15,000  cub  ft 
In  heating  buildings  care  should  be  taken  to  supply  the  neces- 
PROPERTIES    OF    SATURATED    STEAM. 


25 

ft 

jfc. 

in 

il« 

«/>  O     .3 

<!>.flCL 

D. 

Temperature  1 
in  Degrees 
Fahrenheit. 

Totil  Heat  in 
Heat  Units  at 
32"  I*. 

•3c  • 

§1 

'2  B  a 

Z&x 

a 

i£, 

'i1! 

2.2Si 
X 

c 

ill 

3  S-°  3 

S*o£ 
a 

i  i 

•3S* 

ill 

3       O 

>  .s 

Factor  of  equiv- 
alent Evapor- 
ation at  212° 
Fahrenheit. 

(  >    < 

1 

101.99 

1113.1 

70.0 

10430 

0.00299 

334  50 

0.9661 

2 

120  27 

1120.5 

94.4 

1026  1 

0  00570 

173.60 

.9738 

',  . 

3 

141  02 

1125.1 

109.8 

1015.3 

0  00844 

118  50 

.9780 

t  .    * 

.      4 

15309 

11280 

1214 

1007  2 

o  o;  107 

90.33 

.9822 

.5 

162  34 

1131.5 

1307 

1000.8 

001300 

73.21 

.9853 

.. 

•0 

17014 

11338 

138.0 

093  2 

001C-22 

61  05 

9870 

7 

176.80 

1135.9 

145.4 

O'JO  5 

0.01874 

5339 

9897 

8 

182.92 

1137.7 

151.5 

980.2 

002125 

47.00 

9916 

'  ^'.  .  . 

9 

188.33 

1139.4 

1569 

98-2.5 

0  02374 

42.12 

.9934 

?.-.- 

i    10 

193.25 

1140.9 

1619 

9790 

0.02621 

33.15 

.9949 

0 

14.7 

21200 

1146.6 

1807 

9600 

003793 

2078 

I  0000 

,     Q3 

15 

21303 

1146.9 

181.8 

965  1 

0.03820 

20.14 

10003 

•  5.3 

20 

22795 

1151.5 

1969 

954.6 

0.050-23 

l!).01 

10051 

10.3 

25 

24004 

1155.1 

209.1 

9400 

0.06199 

1013 

1.0099 

15.3 

30 

25027 

1158.3 

219.4 

9389 

0.073CO 

13.59 

1.0129 

20.3 

35 

259.19 

11010 

228.4 

932.6 

0.0350S 

11.75 

10157 

25.3 

40 

207.13 

11034 

236.4 

9270 

0.09044 

1037 

10183 

30.3 

45 

27429 

1105.0 

243.6 

9220 

0.1077 

9.235 

1.0205 

35.3 

50 

280  85 

11070 

250.2 

9174 

0.1188 

8.418 

10225 

40.3 

55 

28(5.89 

11794 

2563 

913.1 

0.1299 

7098 

1.0245 

45.3 

60 

29251 

1171.2 

261.9 

9093 

0.1409 

7.097 

1.0263 

60.3 

65 

29777 

1172.7 

267.2 

9059 

0.1519 

6.583 

1.0280 

55.3 

70 

302  71 

1174.3 

272.2 

902.1 

0.1028 

6143 

10295 

CO.  3 

75 

30738 

11757 

276.9 

8988 

01736 

5.700 

1.0309 

65.3 

80 

311  80 

11770 

281.4 

8950 

0.1S43 

5426 

1.0323 

70.3 

85 

31602 

11783 

2858 

8925 

0  1951 

5.126 

1.0337 

75.3 

90 

320.04 

11796 

2900 

8896 

0  2058 

4.859 

1.0350 

80.3 

95 

323  89 

1180.7 

294.0 

8807 

0.2105 

4.019 

10363 

W.3 

100 

32758 

1181.9 

297.9 

884.0 

0.2271 

4.40?- 

10374 

«0.3 

105 

331.13 

1182.9 

301.6 

881  3 

0  2378 

4205 

10385 

95.3 

110 

334.50 

11840 

305.2 

878.8 

0.2484 

4  026 

1.0396 

100.3 

115 

337.80 

11850 

308.7 

8763 

0.2589 

3.862 

10406 

105.3 

120 

34105 

1186.0 

3120 

8740 

02695 

3  711 

1.0416 

110.3 

125 

344.13 

11869 

3152 

871  7 

0.2800 

3.571 

10426 

115  3 

130 

347.12 

1187.8 

3184 

809.4 

02904 

3.444 

1.0435 

125.3 

140 

352.85 

11895 

324.4 

865.1 

0.3113 

3.213 

10453 

135.3 

150 

358  26 

1191.2 

3300 

861.2 

03321 

3.011 

1.0470 

145.3 

160 

36340 

11928 

3354 

8574 

03530 

2833 

1.0486 

155.3 

170 

303.29 

11943 

340.5 

853.8 

0.3737 

2076 

1.0503 

165.3 

180 

372.07 

1195.7 

3454 

8503 

0.3945 

2.535 

1.0517 

175,3 

190 

377.44 

1197.1 

350.1 

847.0 

04153 

2.408 

1.0531 

185.3 

200 

381.73 

1198.4 

8546 

843.8 

04359 

2.294 

1.0545 

210.3 

225 

391.79 

1201.4 

365.1 

8363 

0.4870 

2.051 

1.0576 

235.3 

250 

40099 

1204  2 

3747 

829.5 

0.5393 

1.854 

1.0605 

260.3 

275 

409  50 

12068 

3836 

823.2 

05913 

1.691 

1  0633 

285.3 

300 

41742 

12093 

3919 

817.4 

0.044 

1.553 

10657 

310.3 

325 

42482 

1211.5 

3996 

811.9 

0096 

1.437 

1.0680 

335.3 

350 

431  90 

12137 

4069 

806  8 

0728 

1.8:J7 

1.0703 

360.3 

375 

43840 

1215.7 

414.2 

801.5 

0800 

1  250 

1.0724 

385.3 

400 

445  15 

1217.7 

4214 

796.3 

0.853 

M72 

1.0745 

.485.3 

500 

466  57 

1224  2 

4443 

7799 

1  005 

0939 

1  0313 

136  STEAM  BOILERS. 

•ary  moisture  to  keep  the  air  from  becoming  "dry"  and  uncom- 
fortable. For  comfort,  air  should  be  kept  at  about  "50  per  cent, 
•aturated."  This  would  require  one  pound  of  vapor  to  be  added 
each  2,500  cubic  feet  heated  from  32°  to  70°. 

Care  of  Boilers. 

1.  Safety   Valves. — Great  care  should  be  exercised  to   see   that 
these  valves  are  ample  in  size  and  in  working  order.     Overloading 
or  neglect  frequently  lead  to  the  most  disastrous  results.      Safety 
valves  should  be  tried  at  least  once  every  day  to  see  that  they 
will  act  freely. 

2.  Pressure  Gauge. — The  steam  gauge  should  stand  at  zero  when 
the  pressure  is  off,  and  it  should  show  same  pressure  as  the  safety 
valve  when  that  is  blowing  off.     If  not,  then  one  is  wrong,   and 
the  gauge  should  be  tested  by  one  known  to  be  correct. 

3.  Water  Level. — The  first  duty  of  an  engineer  before  starting 
or  at  the  beginning  of  his  watch,  is  to  see  that  the  water  is  at 
the  proper  height.     Do  not  rely  on  glass  gauges,   floats   or  water 
alarms,  but  try  the  gauge  cocks.     If  they  do  not  agree  with  water 
gauge,  learn  the  cause  and  correct  it. 

4.  Gauge  Cocks  and  Water  Gauges  must  be  kept  clean.     Water 
gauge  should  be  blown  out  frequently,  and  the  glasses  and  pas- 
sages to  gauge  kept  clean. 

5.  Feed   Pump    or   Injector. — These    should   be   kept   in   perfect 
order,  and  be  of  ample  size.    It  is  always  safe  to  have  two  meana 
of   feeding   a   boiler.      Check    valves,    and    self-acting   feed   valves 
should  be  frequently  examined  and  cleaned.     Satisfy  yourself  fre- 
quently that  the  valve  is  acting  when  the  feed  pump  is  at  work. 

6.  Low    Water. — In   case   of   low   water,    immediately   cover  the 
fire   with   ashes    (wet   if   possible)   or  any   earth   that   may   be   at 
hand  .  If  nothing  else  is  handy  use  fresh  coal.     Draw  fire  as  soon 
as  it  can  be  done  without  increasing  the  heat.     Neither  turn  on 
the  feed,  start  or  stop  engine,  or  lift  safety  valve  until  fires  are 
out,  and  the  boiler  cooled  down. 

7.  Blisters  and  Cracks. — These  are   liable  to  occur  in  the  best 
plate  iron.     When  the  first  indication   appears   there  must  be  no 
delay  in  having  it  carefully  examined  and  properly  cared  for. 

8.  Fusible    Plugs,    when    used,    must    be    examined    when    the 
boiler  is  cleaned,   and  carefully  scraped  clean  on  both  the  water 
and  fire  sides,  or  they  are  liable  not  to  act. 

9.  Firing. — Fire  evenly  and  regularly,  a  little  at  a  time.     Mod- 
erately thick  fires  are  most  economical,   but  thin   firing  must  be 
used  where  the  draught  is  poor.     Take  care  to  keep  grates  evenly 
covered,  and  allow  no  air-holes  in  the  fire.     Do  not   "clean"  fires 
oftener    than    necessary.      With    bituminous    coal,    a    "coking   fire," 
1.  e.,  firing  in  front,  shoving  back  when  coked,  gives  best  results 
if  properly  managed. 

10.  Cleaning. — All  heating  surfaces  must  be  kept  clean  outside 
and   in,   or  there   will  be  a  serious   waste  of  fuel.      Never  allow 
over    1/16    inch    scale    or    soot    to    collect    on    surfaces    between 
cleanings.     Handholes  should  be  frequently  removed  and  surfaces 
examined,  particularly  in  case  of  a  new  boiler,  until  proper  inter- 
vals have  been  established  by  experience. 

The  exterior  of  tubes  can  be  kept  clean  by  the  use  of  blowing 
pipe  and  hose.  In  using  smoky  fuel,  it  is  best  to  occasionally 
brush  the  surfaces  when  steam  is  off. 

11.  Hot  Feed  Water. — Cold  water  should  never  be  fed  into  any 
boiler  when  it  can  be  avoided,  but  when  necessary  it  should  be 
caused  to  mix   with   the   heated   water  before   coming  in   contact 
with  any  portion  of  the  boiler. 

12.  Foaming. — When    foaming    occurs    in    a    boiler,    checking 
the  outflow  of  steam   will   usually  stop  it.     If  caused   by  dirty 


STEAM  BOILERS.  137 

water,  blowing  down  and  pumping  up  will  generally  cure  it.     In 
cases  of  violent  foaming,  check  the  draft  and  fires. 

13.  Air  Leaks. — Be  sure  that  all  openings  for  admission  of  air 
to  boiler  or  flues,  except  through  the  fire,  are  carefully  stopped. 
This  is  frequently  an  unsuspected  cause  of  serious  waste. 

14.  Blowing   Off. — If   feed-water  is  muddy   or   salt,   blow  off  a 
portion  frequently,   according  to  condition  of  water.     Empty  the 
boiler  every  week  or  two,  and  fill  up  afresh.     When  surface  blow- 
cocks  are  used,  they  should  be  often  opened  for  a  few  minutes  at 
a  time.     Make  sure  no  water  is  escaping  from  the  blow-off  cock 
when  it  is  supposed  to  be  closed.    Blow-off  cocks  and  check-valves 
should  be  examined  every  time  the  boiler  is  cleaned. 

15.  Leaks. — When  leaks  are  discovered,  they  should  be  repaired 
as  soon  as  possible. 

16.  Blowing  Off. — Never  empty  the  boiler  while  the  brick-work 
is  hot. 

17.  Dampness. — Take  care  that  no  water  comes  in  contact  with 
the  exterior  of  the  boiler  from  any  cause,  as  it  tends  to  corrode 
and   weaken   the   boiler.   Beware   of  all   dampness   in   seatings   or 
coverings. 

18.  Galvanic  Action. — Examine  frequently  parts  in  contact  with 
copper  or  brass,   where  water  is  present,   for  signs  of  corrosion. 
If  water  is  salt  or  acid,   some  metallic  zinc  placed  in  the  boiler 
will  usually  prevent  corrosion,  but  it  will  need  attention  and  re- 
newal from  time  to  time. 

19.  Rapid   Firing. — In    boilers    with   thick   plates    or    seams    ex- 
posed  to   the   fire,    steam   should   be   raised   slowly,   and   rapid   or 
intense  firing  avoided. 

20.  Standing  Unused. — If  a  boiler  is  not  required  for  some  time, 
empty  and  dry  it  thoroughly.    If  this  is  impracticable,  fill  It  quite 
full  of  water,  and  put  in  a  quantity  of  common   washing  soda. 
External  parts  exposed  to  dampness  should  receive  a  coating  of 
linseed  oil. 

21.  General    Cleanliness. — All    things    about    the    boiler    room 
should   be   kept   clean   and   in   good   order.      Negligence   tends   to 
waste  and  decay. 

Rules  for  Conducting  Boiler  Test. 

The  Committee  of  the  A.  S.  M.  E.  on  Boiler  Tests,  consisting  of 
Wm.  Kent  (chairman),  J.  C.  Hoadley,  R.  H.  Thurston,  Chas.  E1. 
Emery,  and  Chas.  T.  Porter,  recommended  the  following  code  of 
rules  for  boiler  tests  (Trans.,  vol.  vi.,  p.  256)  : 

Preliminaries  to  a   Test. 

I.  In   preparing  for  and  conducting  trials  of  steam   boilers   the 
specific  object  of  the  proposed  trial  should  be  clearly  defined  and 
steadily  kept   in   view. 

II.  Measure   and  record   the   dimensions,   position,   etc.,   of  grate 
and  heating  surfaces,  flues  and  chimneys,  proportion  of  air  space 
in  the  grate  surface,  kind  of  draught,  natural  or  forced1. 

III.  Put  the  boiler  in  good  condition.     Have  heating  surface  clean 
inside  and  out,  grate  bars  and  sides  of  furnace  free  from  clinkers, 
dust  and  ashes  removed  from  back  connections,   leaks  in  masonry 
stopped,   and   all   obstructions  to  draught   removed.      See   that  the 
damper  will  open  to  full  extent,  and  that  it  may  be  closed  when 
desired.     Test  for  leaks  in  masonry  by  firing  a  little  smoky  fuel  and 
immediately  closing  damper.     The  smoke  will  then  escape  through 
the  leaks. 

IV.  Have   an  understanding  with   the  parties  In   whose   interest 
the  test  is  to  be  made  as  to  the  character  of  the  coal  to  be  used. 
The  coal  must  be  dry,  or,  if  wet,  a  sample  must  be  dried  carefully 
and  a  determination  of  the  amount  of  moisture  in  the  coal  made, 


138  STEAM  BOILERS. 

and  the  calculation  of  the  results  of  the  test  corrected  accordingly. 
Wherever  possible,  the  test  should  be  made  with  standard  coal  of 
a  known  quality.  For  that  portion  of  the  country  east  of  the  Al- 
legheny Mountains  good  anthracite  egg  coal  or  Cumberland  semi- 
bituminous  coal  may  be  taken  as  the  standard  for  making  tests. 
West  of  the  Allegheny  Mountains  and  east  of  the  Missouri  River, 
Pittsburg  lump  coal  may  be  used.  * 

V.  In  all  important  tests  a  sample  of  coal  should  be  selected  for 
chemical  analysis. 

VI.  Establish  the  correctness  of  all  apparatus  used  in  the  teat 
for   weighing  and   measuring.     These   are :    1.  Scales  for   weighing 
coal,  ashes,  and  water.     2.  Tanks,  or  water  meters  for  measuring 
water.     Water-meters,  as  a  rule,  should  only  be  used  as  a  check  on 
other    measurements.      For    accurate    work    the    water    should    be 
weighed  or  measured  in  a  tank.     3.  Thermometers  and  pyrometers 
for  taking  temperatures  of  air,  steam,  feed  water,  waste  gases,  etc. 
4.  Pressure  gauges,  draught  gauges,  etc. 

VII.  Before  beginning  a  test,   the  boiler  and  chimney  should  be 
thoroughly  heated  to  their  usual  working  temperature.     If  the  boiler 
is  new,  it  should  be  in  continuous  use  at  least  a  week  before  testing, 
so  as  to  dry  the  mortar  thoroughly  and  heat  the  walls. 

VIII.  Before  beginning  a  test,  the  boiler  and  connections  should1  be 
free   from    leaks,    and   all   water    connections,    including   blow    and 
extra   feed   pipes,    should   be    disconnected   or    stopped   with   blank 
flanges,  except  the  particular  pipe  through  which  water  is  to  be  fed 
to  the  boiler  during  the  trial.     In  locations  where  the  reliability  of 
the  power  is  so  important  that  an  extra  feed  pipe  must  be  kept  in 
position,   and   in  general   when   for  any   other   reason   water  pipes 
other  than  the  feed  pipes  cannot  be  disconnected,  such  pipes  may 
be  drilled  so  as  to  leave  openings  in  their  lower  sides,  which  should 
be  kept  open  throughout  the  test  as  a  means  of  detecting  leaks,  or 
accidental  or  unauthorized  opening  of  valves.     During  the  test  the 
blow-off  pipe  should  remain  exposed. 

If  an  injector  is  used  it  must  receive  steam  directly  from  the 
boiler  being  tested,  and  not  from  a  steam  pipe  or  from  any  other 
boiler. 

See  that  the  steam  pipe  is  so  arranged  that  water  of  condensation 
cannot  run  back  into  the  boiler.  If  the  steam  pipe  has  such  an  in- 
clination that  the  water  of  condensation  from  any  portion  of  the 
steam  pipe  system  may  run  back  into  the  boiler,  it  must  be  trapped 
so  as  to  prevent  this  water  getting  into  the  boiler  without  being 
measured. 

Starting  and  Stopping  a  Test. 

A  test  should  last  at  least  ten  hours  of  continuous  running,  and 
twenty-four  hours  whenever  practicable.  The  conditions  of  the 
boiler  and  furnace  in  all  respects  should  be,  as  nearly  as  possible, 
the  same  at  the  end  as  at  the  beginning  of  the  test.  The  steam 
pressure  should  be  the  same,  the  water  level  the  same,  the  fire 
upon  the  grates  should  be  the  same  in  quantity  and  condition,  and 
the  walls,  flues,  etc.,  should  be  of  the  same  temperature.  To  secure 
as  near  an  approximation  to  exact  uniformity  as  possible  in  condi- 
tions of  the  fire  and  in  temperatures  of  the  walls  and  flues,  the  fol- 
lowing method  of  starting  and  stopping  a  test  should  be  adopted : 

X.  Standard  Method. — Steam  being  raised  to  the  working  pres- 
sure, remove  rapidly  all  the  fire  from  the  grate,  close  the  damper, 
clean  the  ash  pit,  and  as  quickly  as  possible  start  a  new  flre  with 
weighed  wood  and  coal,  noting  the  time  of  starting  the  test  and  the 

*  These  coals  are  selected  because  they  are  about  the  only  eoali 
which  contain  the  essentials  of  excellence  of  quality,  adaptability 
to  various  kinds  of  furnaces,  grates,  boilers,  and  methods  of  firing, 
and  wide  distribution  and  general  accessibility  in  the  markets. 


STEAM  BOILERS.  139 

height  of  the  water  level  while  the  water  Is  in  a  quiescent  state, 
just  before  lighting  the  fire. 

At  the  end  of  the  test  remove  the  whole  fire,  clean  the  grates  and 
ash  pit,  and1  note  the  water  level  when  the  water  is  in  a  quiescent 
state ;  record  the  time  of  hauling  the  fire  as  the  end  of  the  test. 
The  water  level  should  be  as  nearly  as  possible  the  same  as  at  the 
beginning  of  the  test.  If  it  is  not  the  same,  a  correction  should  be 
made  by  computation,  and  not  by  operating  pump  after  test  is  com- 
pleted. It  will  generally  be  necessary  to  regulate  the  discharge  of 
steam  from  the  boiler  tested  by  means  of  the  stop-valve  for  a  time 
while  fires  are  being  hauled  at  the  beginning  and  at  the  end  of  the 
test,  in  order  to  keep  the  steam  pressure  in  the  boiler  at  those  times 
up  to  the  average  during  the  test. 

XI.  Alternate  Method. — Instead   of  the   Standard   Method   above 
described,   the   following  may   be  employed!  where   local   conditions 
render  it  necessary : 

At  the  regular  time  for  slicing  and  cleaning  fires  have  them  burned 
rather  low,  as  is  usual  before  cleaning,  and  then  thoroughly  cleaned ; 
note  the  amount  of  coal  left  on  the  grate  as  nearly  as  it  can  be 
estimated  ;  note  the  pressure  of  steam  and  the  height  of  the  water 
level — which  should  be  at  the  medium  height  to  be  carried  through- 
out the  test — at  the  same  time ;  and  note  this  time  as  the  time  of 
starting  the  test.  Fresh  coal,  which  has  been  weighed,  should  now 
be  fired.  The  ash  pits  should  be  thoroughly  cleaned  at  once  after 
starting.  Before  the  end  of  the  test  the  fires  should  be  burned  low, 
just  as  before  the  start,  and  the  fires  cleaned  in  such  a  manner  as 
to  leave  the  same  amount  of  fire,  and  in  the  same  condition,  on 
the  grates  as  at  the  start.  The  water  level  and  steam  pressure 
should  be  brought  to  the  same  point  as  at  the  start,  and  the  time 
of  the  ending  of  the  test  should  he  noted  just  before  fresh  coal  is 
fired. 

During  the  Test. 

XII.  Keep  the  Conditions  Uniform. — The  boiler  should  be  run  con- 
tinuously, without  stopping  for  meal  times  or  for  rise  or  fall  of  pres- 
sure of  steam  due  to  change  of  demand  for  steam.     The  draught 
being  adjusted  to  the  rate  of  evaporation  or  combustion  desired  be- 
fore the  test  is  begun,  it  should  be  retained  constant  during  the  test 
by  means  of  the  damper. 

If  the  boiler  is  not  connected  to  the  same  steam  pipe  with  other 
boilers,  an  extra  outlet  for  steam  with  valve  in  same  should  be 
provided,  so  that  in  case  the  pressure  should  rise  to  that  at  which 
the  safety  valve  is  set  it  may  be  reduced  to  the  desired  point  by 
opening  the  extra  outlet,  without  checking  the  fires. 

If  the  boiler  is  connected  to  a  main  steam  pipe  with  other  boilers, 
the  safety  valve  on  the  boiler  being  tested  should  be  set  a  few 
pounds  higher  than  those  of  the  other  boilers,  so  that  in  case  of  a 
rise  in  pressure  the  other  boilers  may  blow  off,  and  the  pressure 
be  reduced  by  closing  their  dampers,  allowing  the  damper  of  the 
boiler  being  tested  to  remain  open,  and  firing  as  usual. 

All  the  conditions  should  be  kept  as  nearly  uniform  as  possible, 
such  as  force  of  draught,  pressure  of  steam,  and  height  of  water. 
The  time  of  cleaning  the  fires  will  depend  upon  the  character  of  the 
fuel,  the  rapidity  of  combustion,  and  the  kind  of  grates.  When  very 
good  coal  is  used,  and  the  combustion  not  too  rapid,  a  ten-hour  test 
may  be  run  without  any  cleaning  of  the  grates,  other  than  just 
before  the  beginning  and  just  before  the  end  of  the  test.  But  in 
case  the  grates  have  to  be  cleaned  during  the  test,  the  intervals  be- 
tween one  cleaning  and  another  should  be  uniform. 

XIII.  Keeping  the  Records. — The  coal  should  be  weighed  and  de- 
livered to  the  firemen  in  equal  portions,  each  sufficient  for  about 


140 


STEAM  BOILERS. 


one  hour's  run,  and  a  fresh  portion  should  not  be  delivered  until 
the  previous  one  has  all  been  fired.  The  time  required  to  consume 
each  portion  should  be  noted,  the  time  being  recorded  at  the  instant 
of  firing  the  first  of  each  new  portion.  It  is  desirable  that  at  the 
same  time  the  amount  of  water  fed  into  the  boiler  should  "be 
accurately  noted'  and  recorded,  including  the  height  of  the  water  in 
the  boiler  and  the  average  pressure  of  steam  and  temperature  of  feed 
during  the  time.  By  thus  recording  the  amount  of  water  evaporated 
by  successive  portions  of  coal,  the  record  of  the  test  may  be  divided 
into  several  divisions,  if  desired,  at  the  end  of  the  test,  to  discover 
the  degree  of  uniformity  of  combustion,  evaporation,  and  economy 
at  different  stages  of  the  test. 

XIV.  Priming  Tests. — In  all  tests  in  which  accuracy  of  results 
is  important,  calorimeter  tests  should  be   made  of  the  percentage 
of  moisture  in   the  steam,   or  of  the   degree  of  superheating.     At 
least  ten  such  tests  should*  be  made  during  the  trial  of  the  boiler, 
or  so  many  as  to  reduce  the  probable  average  error  to  less  than  one 
per  cent.,  and  the  final  records  of  the  boiler  test  corrected  according 
to  the  average  results  of  the  calorimeter  tests. 

On  account  of  the  difficulty  of  securing  accuracy  in  these  tests, 
the  greatest  care  should  be  taken  in  the  measurements  of  weights 
and  temperatures.  The  thermometers  should  be  accurate  within  a. 
tenth,  of  a  degree,  and  the  scales  on  which  the  water  is  weighed  to 
within  one  hundredth  of  a  pound. 

Analyses  of  Gases. — Measurement  of  Air-Supply,  Etc. 

XV.  In  tests  for  purposes  of  scientific  research,  in  which  the  de- 
termination of  all  the  variables  entering  into  the  test  is  desired, 
certain  observations  should  be  made  which  are  in  general  not  neces- 
sary in  tests  for  commercial  purposes.     These  are  the  measurement 
of  the  air  supply,  the  determination  of  its  contained!  moisture,  tht 
measurement  and  analysis  of  the  flue  gases,  the  determination  of 
the  amount  of  heat  lost  by  radiation,  of  the  amount  of  infiltration 
of  air  through  the  setting,  the  direct  determination  by  calorimeter 
experiments   of   the    absolute   heating   value   of  the   fuel,    and    (by 
condensation   of  all   the   steam   made  by   the  boiler)    of  the   total 
heat  imparted  to  the  water. 

The  analysis  of  the  flue  gases  is  an  especially  valuable  method  of 
determining  the  relative  value  of  different  methods  of  firing,  or  of 
different  kinds  of  furnaces.  In  making  these  analysis  great  care 
should  be  taken  to  procure  average  samples — since  the  composition 
is  apt  to  vary  at  different  points  of  the  flue. 

Record  of  the   Test. 

XVI.  A  "log"  of  the  test  should  be  kept  on  properly  prepared 
Wanks,   containing  headings  as  follows : 


Pressures. 

Temperatures. 

Fuel. 

Feed 
\vatei~ 

Time. 

Barome- 
ter. 

It 

Praught- 
gauge. 

"3 
c 
u 

Boiler- 
room 

2 

u 

Steam. 

V 

e 

3 

H 

^t 

STEAM  BOILERS. 


141 


1.  Date  of  trial 

2.  Duration  of  trial hours. 

DIMENSIONS  AND  PROPORTIONS. 

ipave  space  for  complete  description. 

3.  Grate-surface  —  wide. ...long area sq.ft. 

4.  Water-heating  surface sq.  f t. 

5.  Superheating  surface. sq.  ft. 

;6.  Ratio  of  water-heating  surface  to  grate-stir 

face... , 

AVERAGE  PRESSURES. 

7. '  Steam-pressure  in  boiler,  by  gauge. Ibs. 

8.  Absolute  steam-pressure Ibs. 

9.  Atmospheric  pressure,  per  barometer in. 

10.  Force  of  draught  in  inches  of  water. in. 

AVERAGE  TEMPERATURES. 

11.  Of  external  air. •..,..-,»"... deg. 

12.  Of  fire-room ,.„ deg. 

J3.  Of  steam ........ ".,'. deg. 

14.  Of  escaping  gases.... deg. 

15.  Of  feed-water. . . .  .^. ..... ....... .  -        de 

•  FUEL. 

16.  Total  amount  of  coal  consumed   Ibs. 

1 7."  Moisture  in  coal per  cent. 

18.  Dry  coal  consumed.  .'...'••••••  ••*•••**•  .» Ibs. 

19.  Total  refuse,  dry pounds  = per  cent. 

20.  Total  combustible  (dry  weight  of  coal,  Item 

18;  less  refuse.  Item  19) Ibs. 

21.  Dry  coal  consumed  per  hour. 1 Jbs. 

22.  Combustible  consumed  per  hour. . . . . , .... 

RESULTS  OP  CALORIMETRIC  TESTS. 

.23.  Quality  of  steam,  dry  steam  being  taken  as 
unity : 

24.  Percentage  of  moisture  in  steam. .'..,....,...   per  cent 

25.  Number  of  degrees  superheated.. ............       deg. 

WATER. 

26.  Total  weight  of  water  pumped  into  boiler  and 

apparently  evaporated  ................   ...         Ibs. 

27.  "Water   actually   evaporated,   corrected   for 

quality  of  steam .........,...'.'       Ibs. 

£8.  Equivalent  water  evaporated  into  dry  steam 
from  and  at  212°  F 

29.  Equivalent  total  heat  derived  from  fuel  in 

British  thermal  units    ...;....., ....- i.     B.T.U 

30.  Equivalent  water  evaporated  into  dry  stenn 

from  and  at  21:2°  F.  ner  lioiir . .- . . . Ibs. 

ECONOMIC  EVAPORATION.  , 

31.  Water  actually  evaporated  per  pound  of  dry 

coal,  from  actual  pressure  and  tempera- 
ture  V....-,...,,  »i.^.;,,;;,,.  v.       Ibs 

^•i.  Equivalent  water  evaporated  per  pound  of 

dry  coal  from  and  at  212°  F. Ibs 

33.  Equivalent  water  evaporated  per  pound  of 
combustible  from  and  at  212°  F. 


-COMMERCIAL  EVAPORATION. 

Equivalent  water  evaporated  per  pound  of 
dry  coal  with  one  sixth  refuse,  at  70  pounds 
gauge-pressure,  from  temperature  of  100° 
F.  =  Item  33  X  0.7249 ,. „.«'„•  '.« 


Ibs 


142 


STEAM  BOILERS. 


RATE  OP  COMBUSTION. 

35LDry  coal  actually  burned  per  square  foot  of 
grate^Rurface  per  hour.  .•  .  .  .  .  •  

Ibs. 
Its. 
Ibs. 
Ibs. 

Ibs, 
Ibs, 
Ibs. 

ii)s' 

H.P 

H.P. 
per  cent 

•p          -'             ••_"..'-       ^  Per  sq.  ft.  of  grate- 
«/»     I     Consumption  of  dry  |     surface...... 
,o"'    !  coal  per  hour.  .  Coal  (  Persq.  ft.  of  watei- 
oo'  1  assumed     with     one  f     heating  surface.. 
'  •       1  sixth  refuse.             '     •]  Per  sq.  ft.  of  feast 
I                                       J:    area  for  draught. 

RATE  OP  EVAPORATION. 

89.  Water  evaporated  from  and  at  212°  F.  per 
sq.  ft.  of  heating-surface  per  hour......  

f     Water     evaporated!  ^^e  of*?^ 

40.    i  per   hour   from    tenv    r           ff  '  «  jVl'*; 
;41.  \  perature    of    100°    F^     i^JSiSSuffiST 
«.  Jinto  st.am  of  70  Ibs.    ,4  Jq  tl  or  le^s.' 
{  gauKe-pressure.            /    ao?a?for  draught. 

COMMERCIAL  HORSE-POWKR.  -^ 

43.  On  basis  of  thirty  pounds  of  water  per  hour 
evaporated  from  temperature  of  100°  F. 
into  steam  of   TO  pomulS  Kauge-pressure 
(—  3U-£  Ibs  from  and  at  212') 

?4i  Horse  powei1,  builders'  j-aring,  at  square 
feet  per  hoi-se  power.-,  
4r>.  Per  cent  developed  above,  or  below,  rating§. 

Reporting  the  Trial. 

XVII.  The  final  results  should  be  recorded  upon  a  properly  pre- 
pared blank,  and  should  include  as  many  of  the  following  Items  as 
are  adopted  for  the  specific  object  for  which  the  trial  is  made. 

Results  of  the  trial  of  a   

Boiler  at  

To  determine   

NOTES  ON  STEAM  BOILERS: 


Pumps 


Pressure  and  Head. 

To  find  the  pressure  in  Ibs.  per  square  inch  of  a  column  of 
water,  multiply  the  height  of  the  column  in  feet  by  .433. 

To  find  the  height  of  a  column  of  water  in  feet,  the  pressure 
being  known,  multiply  the  pressure  shown  on  gauge  by  2.309. 

The  mean  pressure  of  the  atmosphere  is  usually  estimated  at 
14.7  Ibs.  per  square  inch,  so  that  with  a  perfect  vacuum  it  will 
•ustain  a  column  of  mercury  29.9  inches,  or  a  column  of  water 
83.9  feet  high,  at  sea  level. 

PRESSURE     AND     HEAD. 


Fret 

*»d. 

Square  Inch. 

Feet 
Head. 

Pressure  per 
Square  Inch. 

Feet 
Head. 

Pressure  per 
Square  Inch. 

Feel 
Head. 

Pressure  per 

Feet 
Head. 

Pressure  per 
Square  Inch. 

1 

0.43 

64 

.         27.72 

127 

55.01 

190 

82.30 

253 

109.50 

9 

0.86 

65 

28.15 

128 

55.44 

191 

82.73 

254 

110.03 

3 

1.30 

66 

28.58 

129 

55.88 

192 

83.17 

255 

110.46 

4 

1.73 

67 

130 

56.31 

193 

83.60 

256 

110.80 

.* 

2.16 

68 

29^45 

131 

56.74 

194 

84.03 

257 

111.88 

B 

2.59 

69 

29.88 

132 

57.18 

195 

84.47 

258 

111.78 

7 

3.03 

70 

30.32 

133 

57.61 

196 

84.90 

259 

112.19 

8  . 

3.46 

71 

30.75 

134 

58.04 

197 

85.33 

260 

112.02 

B 

3.89 

72 

31.18 

135 

58.48 

198 

85.76 

261 

'    113.06 

10 

4.33 

73 

31.62 

136 

58.91 

199 

86.20 

113.49 

11 

4.76 

74 

32.05 

137 

59.34 

200 

86.63 

263 

113.93 

12 

5.20 

75- 

138 

59.77 

201 

87.07 

264 

114.36" 

13 

5.63 

76 

32!92 

139 

60.21 

202   . 

87.50 

265 

114.79 

14 

6.06 

77 

140 

6064 

203 

87.93 

266 

115.22 

16 

6.49 

78 

88)78 

141 

61  07 

201 

88.36 

267 

116.66 

16 

6.93 

79 

34.21 

142 

61.51 

205 

88.80 

268 

116.09 

17 

7.36 

80 

34.65 

143 

61.94 

206 

89.23 

289 

116.62 

18 

7.79 

81 

35.08 

144 

62.37 

207 

89.66 

270 

116.96 

19 

8.22 

82 

35.52 

145 

62.81 

208 

90.10 

271 

117.39 

20 

8.66 

83 

SS.HS 

146 

68.24 

209 

90.53 

272 

117.82 

21 

9.09 

84 

36.39 

147 

63.67 

210 

90.96 

273 

118.26 

22 

9.53 

85 

36.82 

148 

64.10 

211 

91.39 

274 

118.69 

23 

9.96 

37.25 

149 

64.54 

212 

91.83 

273 

119.12 

24 

10.39 

87 

37.68 

150 

64.97 

213 

92.26 

276 

119.56 

25 

10.82 

88 

38.12 

151 

65.40 

214 

92.69 

277 

119.99 

26 

11.26 

89 

38.55 

152 

65.84 

215 

93.13 

278 

120.42 

27 

11.69. 

90 

38.98 

153 

66.27 

216 

93.56 

279 

120.85 

28 

12.12 

91 

39.42 

154 

66.70 

.217 

93.99 

280 

121.29 

29 

12.55 

92 

39.85 

155 

67.14 

218 

94.43 

281 

121.72 

30 

12.99 

93 

40.28 

156 

67.57 

219 

94.86 

282 

122.15 

31 

13.42 

94 

40.72 

157 

68.00 

220 

95.30 

283 

122.59 

32 

13.86 

95 

41.15 

158 

68.43 

221 

95.73 

284 

123.02 

33 

14.29 

96 

41.58 

159 

68.87 

96.16 

285 

123.45 

34 

14.72 

97 

42.01 

160 

69.31 

223 

96.60 

286 

123.89 

35 

15.16 

98 

42.45 

161 

69.74 

224 

97.03 

287 

124.32 

36 

15.59 

99 

42.88 

162 

70.17 

225 

97.46 

288 

124.75 

37 

16.02 

100 

43.31 

163 

70.61 

226 

97.90 

289 

125.18 

38 

16.45 

101 

43.75 

164 

71.04 

227 

98.a3 

290 

125.62 

39 

16.89 

102 

44.18 

165 

71.47 

228 

98.76 

291 

126.06 

40 

17.32 

103 

44.61 

166 

71.91 

229 

99.20 

292 

126.48 

41 

17.75 

104 

45.05 

167 

72.34 

230 

99.63 

293 

126.92 

42 

18.19 

105 

45.48 

168 

72.77 

231 

100.06 

294 

127.35 

43 

106 

45.91 

73.20 

232 

100.49' 

295 

127.78 

44 

mo5 

107 

46.34 

170 

73.64 

233 

100.93 

296 

128.22 

45 

19.49 

108 

46.78 

171 

74.07 

234 

101  36 

297 

128.65 

46 

19.92 

109 

47.21 

172 

74.50 

235 

101  79 

298 

129.08 

47 

20.35 

110 

47.64 

173 

74.94 

236 

10223 

299 

12051 

48 

20.79 

111 

48.08 

1  4 

75.37 

237 

102  66 

300 

129.95 

49 

21.22 

112 

48.51 

1  5 

75.8C 

238 

103.09 

310 

134.28 

50 

21.65 

48.94 

1-6 

76.23 

239 

103.53 

320 

138.62 

51 

22.09 

114 

49.38 

177 

76.67 

240 

103.96 

330 

142.96 

52 

22.52 

115 

49.81 

1~8 

77.10 

241 

10439 

340 

147.28 

53 

22.95 

116 

50.24 

1-9 

77.53 

242 

10483 

350 

151.61 

54 

2330 

117 

50.68 

180 

77.97 

243 

10526 

360  ' 

155.94 

55 

23.82 

118 

51.11 

181 

78.40 

244 

10569 

370 

160.27 

56 

24.26 

119 

51.54 

182 

78.84 

245 

106.13 

380 

""  164.61 

57 

24.69 

120 

51.98 

183 

79.27 

246 

10656 

390 

168.94 

58 

25.12 

'   121 

52.41 

184 

79.70 

247 

10699 

400 

173.27 

59 

25.55 

122 

52.84 

185 

8014 

218 

107.43 

500    . 

216.58 

60 

25.99 

123 

53.28 

106 

80.57 

249 

107.86 

600 

259.90 

61 

26.42 

124 

53.71 

187 

81  00 

250 

10829 

700 

303.22 

62 

26'a5 

125 

54.15 

188 

8143 

251 

108.73 

800 

346.54 

63 

27.29 

126 

54.58 

18!) 

81.87 

252 

10916 

100 

38986 

1000 

43318 

144  PUMPS. 

Horse-Power. 

The  theoretical  horse-power  required  to  elevate  water  to  a 
glren  height  is  found  by  multiplying  the  total  weight  of  water 
in  Ibs.  by  the  height  in  ft.  and  dividing  by  33,000;  or,  by  multi- 
plying the  gallons  per  minute  by  the  height  in  ft.  and  dividing 
by  4,000.  (Allowance  of  25  per  cent,  should  be  added  for  friction.) 

PUMP   HORSE   POWER   REQUIRED   TO    RAISE   WATER. 


.'.06 
012 
019 
.025 

M/ 

lOO7 

ia«' 

is<y 

5 
10 
15 
20 

.012 
.025 
.037 
.050 

.019 
.037 
.056 
.075 

.025 
.050 
.075 
.100, 

031 
'062 
.094 
.125 

.037 
.075 
.112 
.150 

.044 
.087 
.131 
.175 

.05 
.10 
.15 
.20 

M 
.11 
.17 
.22 

.06 
.12 
.19 
.25 

.07 
.15 
.22 
.30 

.09 
.19 
.28 
.37 

.11 

.22 
.34 
.45 

.12 
.25 
.37 
.50 

16 
.31 
.47 
62 

.19. 
.37 
.56i 

.75< 

25 
30 
35 
40 

.031 
.037 
048 

05IJ 

.062 
.075 
.087 
.100 

.093 
.112 
.131 
.150 

.125 
.150 
.175 
.200 

.156 
.187 
.219 
.250 

.187 
.225 
.262 
.300 

.219 
.262 
306 
.350 

.25 

.30 
.35 
.40 

.28 

.34 
.39 
.45 

.31 
.37 
,44 
.50 

.37 
.45 
.52 

.60 

.47 
.56 
.66 
.75 

.56 
.67 
.79 
.90 

.62 
.75 
.87 
1.00 

78 
.94 
1.08 
1.25 

.94 
1.12 
1.31 
1.50 

45 
50 
60 
75 

.056 
.002 
075 
093 

.112 
125 
.150 
.187 

.168 
.187 
.225 
.281 

.225 
.250 
.300 
.375 

.281 
.312 
.375 
.469 

.337 
.375 
.450 
.562 

.394 
.437 
.525 
.656 

.45 
.50 
.00 
.75 

.51 
M 

.67 

.84 

.50 
.62 
.75 
.94 

.67 

.75 
.90 
1.12 

.84 

.94 
1.12 
1.40 

1.01 

1.12 
1  35 
1.69 

1.12 
1.25 
1.50 

1.87 

1.41 
1.56 
J.87 
2.34 

1.69! 
1.871 
2.25, 

2.81) 

90 
100 
125 
150 

.112 
,125 
.156 

.187 

.225 
.250 
312 
.375 

.837 
.375 
.469 
.562 

.450 
.500 
.625 
.750 

.562 
.625 
.781 
.937 

.675 
.750 
.937 
1.125 

.787 
.875 
1.094 
1.312 

.90 
LOO 
1.25 
1.50 

1.01 
1.12 
1.41 
1.69 

1.12 
1.25 
1.56 

1.87 

1.35 

1.50 
1.87 
2.25 

1.68 
1.87 
2.34 

2.81 

2.02 
2.25 
2.81 
3.37 

2.25 
2.50 
3.12 
3.75 

2.81 
3.12 
3.91 
4.69 

3371 
3.751 
4.«9> 
5.621 

175 
200 
250 
300 

.219 
.250 
.312 
.375 

.437 
.500 
.625 
-.750 

.656 
.750 
.937 
1.125 

,875 
1.000 
1.250 
1.500 

1.0931.312 
1.25011.500 
1.56311.875 
1.8752.250 

1.531 
1.750 

2.187 
2.625 

1.75 

2  do 
2.50 
3.00 

1.97 

2.25 
2.81 
3.37 

2.19 
2.50 
3.12 
3.75 

2.62 
3.00 
3.75 
4.50 

3.28 
3.75 
4.69 
5.62 

3.94 
4.50 
5.62 
6,75 

4.37 
5.00 
6.25 
7.50 

5.47 
6.25 
781 
9.37 

6.56 
7.50 
^.37) 
1L25! 

350 

400 
500 

.437 
500 
625 

.875  1.312 
I  000  1.500 
1.250  1.875 

1.750 
2.000 
2.500 

2.1872.625 
2.5003.000 
3.1253.750 

3.062 
3.500 
4.375 

3.50 
400 
5.00 

3.94 
4.50 
5.62 

4.37 
5.00 
6.25 

5.25 
6.00 

7.50 

6.,  56 
750 
9.37 

7.87 
9.00 
11.25 

8.75 
10.00 
12.50 

10.94 
12.50 
15.62 

18.12' 
15.00 

18.75 

The  actual  horse-poicer  for  100  ft.  lift  is  1.7  times  the  theoretical 
horse-power,  for  a  200  ft.  lift  1.45  times,  and  for  a  300  ft.  lift 
1.25  times. 

It  is  estimated  that  it  requires  approximately  one  horse-power, 
including  friction,,  to  raise  sixty  gallon*  of  water  per  minute 
thirty-three  feet  high. 

Capacity  of  Pump. 

To  find  the  capacity  of  a  cylinder  in  gallons,  multiply  the  area 
in  inches  by  the  length  of  stroke  in  inches;  divide  this  amount 
by  231  (which  is  the  cubical  contents  of  a  gallon  of  water),  and 
the  quotient  is  the  capacity  in  gallons. 

A  U.  S.  gallon  of  water  weighs  8%  Ibs.  and  contains  231  cubic 
inches.  A  cub.  ft.  of  water  weighs  62.4  Ibs.  and  contains  1,728 
cb.  inches,  or  7.48  gallons. 

To  find  quantity  of  water  elevated  in  one  minute  running  at  100 
feet  of  piston  speed  per  minute,  square  the  diameter  of  water 
cylinder  in  inches  and  multiply  by  4.  Example:  Capacity  of  a 
five-inch  cylinder  is  desired.  The  square  of  the  diameter  Co 
inches)  is  25,  and  multiplied  by  4  gives  100,  which  is  gallons  per 
minute  (approximately). 

To  find  the  diameter  of  a  pump  cylinder  to  move  a  given  quan- 
tity of  water  per  minute  (100  feet  of  piston  travel  being  the 
speed),  divide  the  number  of  gallons  by  4,  then  extract  the  square 
root,  which  will  be  the  required  diameter  in  inches. 


PUMPS. 


145 


TABLE  OF  EFFICIENCY  OF  PUMPING  MACHINES. 


DESCRIPTION. 

Duty  in  Million 
Foot  Pounds  per  no 
Its.  Coal. 

Per  Centage  of  Ther- 
mal   Value   of 
Steam  Used. 

Equivalent  in  Coal 
per  Hourly  Horse- 
power. 

1  Pumping  Engines  1 
Steam  pumps,  large  size.l 
Steam  pumps,  small  size, 
Vacuum  pumps  _ 
Injectors,  lifting  water  only. 

30    to    i  to 
15    to      30* 
8    to      15 
3     to       10 
»     to         5 

3.89    .0    13.25 
1.94          3.89 
1.04    "    1.94 
0.39    "    1.30 
0.26    "    0.61; 

6.68    to    1.95       ' 
13-4      "      6.68 
z|.oo    ;•     13.40 
66.6      "     75.00 

100        "      66.60 

TATsK    OR    LIGHT-SERVICE    DUPLEX    PUMP    (WORKING    PRESSURE 
OF    75    LBS.) 


PLUNGER  AND  RING  PATTERN  PISTON  PATTERN  WATER  EN 

FIG.   63.     DUPLEX    PUMP. 


Sizes. 

jg 

Capacity 

to 

Sizes  of  Pipes. 

. 

2 

per  min. 
at  Given 

V 

0} 

<v 

1 

09 

fe 

Speed. 

0 

P 

•  o 

c 

J2 
i  ">» 

§| 

'"*  ^ 

P, 

CO 

n 

BO 

.5 

r| 

a 

« 

1 

i 

•2|> 

11 

1 

0) 

P 
^o 

"S) 

C 

,g 

•S 

i 

1    : 

_ 

CJ 

1 

JS 
CO 

? 

(3 

O 

1 

O 

3 

t 

02 

W 

^ 

s 

4 

4 

5 

.27 

130 

35 

33 

9J/ 

K 

% 

2 

1J4 

5 

4 

7 

.38 

125 

48 

45^ 

15 

3 

2J4 

gi/ 

5V6 

7 

.72 

125 

90 

15 

% 

3 

2V6 

r-|2 

71^ 

10 

1.91 

110 

210 

'    58 

17 

i 

L<J 

5 

4 

8 

6 

12 

1.46 

100 

146 

67 

i 

V*> 

4 

4 

6 

7 

12 

2.00 

100 

200 

66 

17  " 

3/ 

4 

4 

8 

7 

12 

2.00 

100 

200 

67 

1 

/^ 

5 

4 

8 

8 

12 

2.61 

100 

261 

68 

30 

1 

U: 

5 

5 

10 

8 

12 

2.61 

100 

201 

68^ 

30 

1  V^ 

2 

5 

5 

8 

10 

12 

4.08 

100 

408 

68 

20^ 

1 

\\£ 

8 

8 

10 

10 

12 

4.08 

100 

408 

68^ 

30 

2 

8 

8 

J2_  J 

10 

4.^8 

JOO. 

408 

64 

_24._ 

2 

2}£ 

8 

8 

SINGLE    ACTING    TRIPLEX    PUMP. 


Diameter, 

Pump 
Plungers, 

Stroke 
Plunders.'' 

Caps 
.  gallot 
revolu 
Cranl 

icity, 
:  Shaft. 

Gallons,  per 
min.,  40  rev. 
of  drank 
Shaft. 

Size 
Suction 
Pipe, 
Inches. 

Size 
Delivery 

inPcn!s. 

4 

6 

I  . 

00 

49 

2^2 

2 

S 

6 

I. 

5° 

60' 

3 

2/4 

5 

8 

2. 

00 

80 

3 

2l/4 

6 

8 

.2, 

93 

"7 

4 

3 

7 

8 

4 

,00 

160 

5 

4 

8 

8 

y< 

,  20 

208 

6 

5 

8 

10 

6 

•  50 

260 

6 

5 

Ratio 

of 
Gearing. 

7/4  tO  I 

to  i 

tO  I 

to  i 

tO  I 
tO  I 
tO  I 


146  PUMPS. 

CENTRIFUGAL  PUMPS    (FOR   LIFTS   FROM   15   to  35   FT.) 


FIG    64— CENTRIFUGAL    PUMP. 


If 

il 

|| 

Economical 
Capacity, 
gals,  per 
inin; 

^.  *C  •  — 

si*' 

!* 

ft 

Jl 

Suction, 
pipe,  in. 

Discharpe- 
pipe,  in. 

Economical 
Capacity, 
gals,  per 
in  in. 

H.P.  for 
each  foot 
of  lift. 

jfj 

1« 

j« 

1 
l«i 

25 
70 

-.028 
.05 

65 
230 

10 
12 

10 
12 

10 
12 

3000 
4200 

I.  GO 
2.15 

3000  f 
6800 

a 

2J*> 

2 

100 

.08 

265 

15 

15 

15 

7000 

3.50 

8840 

3 

3J4 

3 

250 

.15 

500 

18 

18 

18 

10000 

5.00 

10000 

4 

4^ 

4 

450 

.27 

680 

24 

24 

24 

18000 

7.60 

9000* 

6 

6. 

5 

700 

.36 

1032 

30 

30 

30 

25000 

10.50 

20000* 

6 
8 

6 
8 

6 

8 

1200 
2000 

.65 
1.  10 

1260 
2460 

36 

36 

36 

35000 

14.75 

22000*. 

Directions  for  Connecting  and  Running  Pumps. 

The  suction  pipe  of  a  pump  should  be  perfectly  air-tight.  A 
leak  In  the  suction  pipe  will  destroy  the  vacuum,  and  prevent 
the  water  rising  in  the  pipe. 

The  suction  and  discharging  pipes  should  be  run  with  as  fe\r 
bends  and  elbows  as  possible,  to  avoid  water-hammer  i.nd  undue 
friction.  The  diameters  should  never  be  less  than  called  for  by 
the  openings  on  the  pumps. 

When  drawing  or  forcing  water  long  distances  or  at  high  speeds, 
the  diameters  of  the  pipes  should  be  greater  than  called  for  by 
the  openings  on  pumps,  and  should  be  large  enough  to  convey  the 
fluids  with  the  minimum  of  friction.  This  is  particularly  essen- 
tial for  the  suction  pipe,  which  has  only  the  atmospheric  pressure 
to  force  the  water  from  the  source  of  supply  to  the  pumps. 

A  strainer  should  be  attached  to  suction  pipe  to  prevent  the 
entrance  of  foreign  substances,  and  the  total  area  of  the  strainer 
holes  should  be  -from,  two  to  five  times  the  area  of  the  pipe. 

A  large  vacuum  chamber  on  suction  pipe  near  the  pump  is 
advantageous,  and  when  high  speeds  are  desired  without  noise, 
becomes  a  necessity. 

Hot  water  cannot  be  lifted  by  suction  any  desirable  height, 
and  the  difficulty  increases  with  the  temperature.  To  handle 
hot  water  efficiently  it  should  gravitate  to  the  pump. 

During  cold  weather,  if  in  an  exposed  situation,  the  pump  and 
pipes  should  be  thoroughly  drained  after  stopping,  to  insure 
safety  against  frost. 


PUMPS.  14? 

The  steam  and  exhaust  pipes  should  be  connected  so  that  they 
may  be  drained  of  their  water  of  condensation.  When  a  steam 
pump  is  not  to  be  used  for  some  time,  the  steam  cylinder  and 
valve  gear  should  be  well  oiled  before  stopping. 

The  stuffing-boxes  should  be  kept  clean  and  carefully  packed, 
to  avoid  excessive  friction  by  being  screwed  down  too  tight. 

Short  Rule  for  Piping  a  Pump.  —  To  find  the  size  of  steam  pipe, 
divide  the  cross-sectional  area  of  steam  piston  by  64.  To  find 
the  size  of  exhaust  pipe  divide  the  cross-sectional  area  of  steam 
piston  by  32.  To  find  the  size  of  the  discharge  pipe  divide  the 
cross-sectional  area  of  plunger  by  3.  To  find  the  size  of  suction 
pipe,  divide  the  cross-sectional  area  of  plunger  by  2.  Give  th« 
water  valves  the  same  area  of  opening  as  the  suction  pipe. 

Duty  Trials  of  Pumping  Engines. 

(Abridged  from  Trans.  A.  S.  M.   E.,  XII,  530.) 

The  new  unit  chosen,  foot  pounds  of  work  per  million  heat 
units  furnished  by  the  boiler  is  the  equivalent  of  100  Ibs.  of 
coal  in  cases  where  each  pound  of  coal  imparts  10,000  heat  units 
to  the  water  in  the  boiler,  or  where  the  evaporation  is  10,000  : 
965.7  =  10,355  Ibs.  of  water  from  and  at  212°  per  pound  of  fuel. 

The  work  done  is  determined  by  plunger  displacement,  after 
making  a  test  for  leakage,  instead  of  by  measurement  of  flow  by 
weirs,  which,  however,  may  help  to  obtain  additional  data. 

The  necessary  data  having  been  obtained,  the  duty  of  an  en- 
gine may  be  computed*  by  the  use  of  the  following  formulae  : 

.  Foot-pounds  of  work  done  __  v  1000  000 

1.  Duty  -  Total  number  of  heat-  units  consumed 

.pounds). 


2.  Percentage  of  leakage  =  ^T^NX  10°  <Per  cent)' 

3.  Capacity  =  number  of  gallons  of  water  discharged  in  24  hours 
_  AXLXNX  7.4805X24    =   A  X  L  X  N  X  1.24675 

D  X  144  & 

4.  Percentage  of  total  frictions, 


TTTTP       A(P±  *>  +  s>x^*  ^1 

"  0X60X33,000  10ft 

L  -  "I.H.P.  ~~"JX 


becomes:  r         A(Tt         •    •*  -i 

Percentage  of  total  frictions  =  [l  -  l^Sp/J  X  100  (per  cent); 

In  these  formulae  the  letters  refer  to  the  following  quantities: 

A  =  Area,  in  square  inches,  of  pump  plunger  or  piston,  corrected 
for  area  of  piston  rod  or  rods. 

P  =  Pressure,  in  pounds  per  square  Inch,  Indicated  by  the  gauge 
on  the  force  main. 

p  =  Pressure,  in  pounds  per  square  Inch,  corresponding  to  in- 
dication of  the  vacuum  gauge  on  suction  main  (or  pressurer  gauge, 
if  the  suction  pipe  is  under  a  head).  The  indication  of  the  vacuum 
gauge,  In  inches  of  mercuBy,  may  be  converted  into  pounds  by  di- 
viding It  by  2.035. 


148  PUMPS. 

8  =  Pressure,  in  pounds  per  square  Inch,  corresponding  to  dis- 
tance between  the  centres  of  the  two  gauges.  The  computation 
for  this  pressure  is  made  by  multiplying  the  distance,  expressed  In 
feet,  by  the  weight  of  one  cubic  foot  of  water  at  the  temperature 
of  the  pump  well,  and  dividing  the  product  by  144. 

L  =  Average  length  of  stroke  of  pump  plunger,  in  feet. 

N  =  Total  number  of  single  strokes  of  pump  plunger  made  dur- 
ing the  trial. 

As  =  Area  of  steam  cylinder,  in  square  inches,  corrected  for 
area  of  piston  rod.  The  quantity  As  X  M.E.P.,  in  an  engine  having 
more  than  one  cylinder,  is  the  sum  of  the  various  quantities  re- 
lating to  the  respective  cylinders. 

Ls  =  Average  length  of  stroke  of  steam  piston,  in  feet. 

Ns  =  Total  number  of  single  strokes  of  steam  piston  during 
trial. 

M.E.P.  =  Average  mean  effective  pressure,  in  pounds  per  square 
inch,  measured  from  the  indicator  diagrams  taken  from  the  steam 
cylinder. 

I.H.P.  =  Indicated  horse  power  developed1  by  the  steam  cylinder. 

G  =  Total  number  of  cubic  feet  of  water  which  leaked  by  the 
pump  plunger  during  the  trial,  estimated  from  the  results  of  the 
leakage  test. 

D    =   Duration  of  trial  in  hours. 

H  =  Total  number  of  heat  units  (B.  T.  U.)  consumed  by  engine 
=  weight  of  water  supplied  to  boiler  by  main  feed-pump  X  total 
heat  of  steam  of  boiler  pressure  reckoned  from  temperature  of 
main  feed  water  -f-  weight  of  water  supplied  by  jacket  pump  X 
total  heat  of  steam  of  boiler  pressure  reckoned  from  temperature 
of  jacket  water  +  weight  of  any  other  water  supplied  X  total  heat 
of  steam  reckoned  from  its  temperature  of  supply.  The  total 
heat  of  the  steam  is  corrected  for  the  moisture  or  superheat  which 
the  steam  may  contain.  No  allowance  is  made  for  water  added  to 
the  feed  water,  which  is  derived  from  any  source,  except  the  engine 
or  some  accessory  of  the  engine.  Heat  added  to  the  water  by  the 
use  of  a  flue  heater  at  the  boiler  is  not  to  be  deducted.  Should1 
heat  be  abstracted  from  the  flue  by  means  of  a  steam  reheater 
connected  with  the  intermediate  receiver  of  the  engine,  this  heat 
must  be  included  in  the  total  quantity  supplied  by  the  boiler. 

Leakage  Test  of  Pump. 

The  leakage  of  an  inside  plunger  (the  only  type  which  requires 
testing)  is  most  satisfactorily  determined  by  making  the  test  with 
the  cylinder  head  removed.  A  wide  board"  or  plank  may  be  tem- 
porarily bolted  to  the  lower  part  of  the  end  of  the  cylinder,  so  as 
to  hold  back  the  water  in  the  manner  of  a  dam,  and  an  opening 
made  in  the  temporary  head  thus  provided  for  the  reception  of  an 
overflow  pipe.  The  plunger  is  blocked  at  some  intermediate  point 
in  the  stroke  (or,  if  this  position  is  not  practicable,  at  the  end 
of  the  stroke),  and  the  water  from  the  force  main  is  admitted  at 
full  pressure  behind  it.  The  leakage  escapes  through  the  over- 
flow pipe,  and1  it  is  collected  in  barrels  and  measured.  The  test 
should  be  made,  if  possible,  with  the  plunger  in  various  positions. 

In  the  case  of  a  pump  so  planned  that  it  is  difficult  to  remove 
the  cylinder  head,  it  may  be  desirable  to  take  the  leakage  from 
one  of  the  openings  which  are  provided  for  the  inspection  of  the 
suction  valves,  the  head  being  allowed  to  remain  in  place. 

It  is  assumed  that  there  is  a  practical  absence  of  valve  leakage. 
Examination  for  such  leakage  should  be  made,  and  if  it  occurs, 
and  it  is  found  to  be  due  to  disordered  valves,  it  should1  be  remedied 
before  making  the  plunger  test.  Leakage  of  the  discharge  valves 
will  be  shown  by  water  passing  down  into  the  empty  cylinder  at 
either  end  when  they  are  under  pressure.  Leakage  of  the  suction 


PUMPS.  149 

valves  will  be  shown  by  the  disappearance  of  water  which  covers 
them. 

If  valve  leakage  is  found  which  cannot  be  remedied  the  quantity 
of  water  thus  lost  should  also  be  tested.  One  method  is  to  meas- 
ure the  amount  of  water  required  to  maintain  a  certain  pressure 
in  the  pump  cylinder  when  this  is  introduced!  through  a  pipe  tem- 
porarily erected,  no  water  being  allowed  to  enter  through  the  dis- 
charge valves  of  the  pump. 

Table  of  Data  and  Results. 

In  order  that  uniformity  may  be  secured,  it  is  suggested  that 
the  data  and  results,  worked  out  in  accordance  with  the  standard 
method,  be  tabulated  in  the  manner  indicated  in  the  following 
scheme  : 

DUTY  TRIAL  OF  ENGINE. 

DIMENSIONS. 

1.  Number   of   steam   cylinders 

2.  Diameter   of   steam   cylinders ins. 

3.  Diameter  of  piston  rods  of  steam  cylinders ins. 

4.  Nominal  stroke  of  steam  pistons ft. 

5.  Number   of   water   plungers 

6.  Diameter    of    plungers ins. 

7.  Diameter  of  piston  rods  of  water  cylinders ins. 

8.  Nominal    stroke    of    plungers ft. 

9.  Net  area   of  steam  pistons sq.  ins. 

10.  Net   area   of  plungers sq.    ins. 

11.  Average  length  of  stroke  of  steam  pistons  during  trial  ft. 

12.  Average  length  of  stroke  of  plungers  during  trial....   ft. 

(Give  also  complete  description  of  plant.) 

TEMPERATURES. 

13.  Temperature  of  water  in  pump  well degs. 

14.  Temperature  of  water  supplied  to  boiler  by  main  feed 

pump    degs. 

15.  Temperature  of  water  supplied  to  boiler  from  various 

other    sources degs. 

FEED    WATER. 

16.  Weight  of  water  supplied  to  boiler  by  main  feed  pump  Ibs. 

17.  Weight    of    water    supplied1    to    boiler    from    various 

other   sources    Ibs. 

18.  Total  weight  of  feed  water  supplied  from  all  sources. .   Ibs. 

PRESSURES. 

19.  Boiler  pressure  indicated  by  gauge Ibs. 

20.  Pressure  indicated  by  gauge  on  force  main Ibs. 

21.  Vacuum  indicated  by  gauge  on  suction  main ins. 

22.  Pressure  corresponding  to  vacuum  given  in  preceding 

line    Ibs. 

23.  Vertical    distance    between    the    centres    of    the    two 

gauges    ins. 

24.  Pressure  equivalent  to  distance  between  the  two  gauges.    Ibs. 

MISCELLANEOUS   DATA. 

25.  Duration   of  trial hrs. 

26.  Total    number    of   single    strokes    during   trial 

27.  Percentage  of  moisture  in  steam  supplied  to  engine,  or 

number  of  degrees  of  superheating %  or  dcg. 

28.  Total  leakage  of  pump  during  trial,  determined  from 

results   of   leakage   test Ibs. 

29.  Mean    effective    pressure,    measured    from    diagrams 

taken    from    steam    cylinders M.E.P. 


150  PUMPS. 

PRINCIPAL   RESULTS. 

30.     Duty     ft.  Ibs. 

81.     Percentage  of  leakage % 

32.  Capacity gals. 

33.  Percentage  of  total  friction % 

ADDITIONAL    RESULTS. 

34.  Number  of  double  strokes  of  steam  piston  per  minute . 

35.  Indicated  horse  power  developed  by  the  various  steam 

cylinders I.H.P. 

36.  Feed  water  consumed  by  the  plant  per  hour Ibs. 

37.  Feed  water  consumed  by  the  plant  per  Indicated  horse- 

power per  hour,  corrected  for  moisture  in  steam ....   Ibs. 

38.  Number  of  beat  units  consumed  per  indicated  horse- 

power per   hour    B.T.U. 

39.  Number  of  heat  units  consumed  per  indicated  horse 

power  per  minute B.T.U. 

40.  Steam  accounted  for  by  indicator  at  cut-off  and  release 

in  the  various  steam   cylinders Ibs. 

41.  Proportion   which  steam   accounted  for   by   indicator 

bears  to  the  feed  water  consumption 

42.  Number  of  double   strokes  of  pump  per  minute.... 

43.  Mean    effective   pressure,    measured   from    pump    dia- 

grams        M.E.P. 

44.  Indicated  borse  power  exerted  in  pump  cylinders....   I.H.P. 

45.  Work  done  (or  duty)  per  100  Ibs.  of  coal ft.  Ibs. 

SAMPLE    DIAGRAM    TAKEN    FROM     STEAM    CYLINDERS. 

(Also,  if  possible,  full  measurement  of  the  diagrams,  embracing 
pressures  at  the  initial  point,  cut-off,  release,  and  compression ;  also 
back  pressure,  and  the  proportions  of  the  stroke  completed  at  the 
various  points  noted.) 

SAMPLE  DIAGRAM   TAKEN   FROM   PUMP    CYLINDERS. 

These  are  not  necessary  to  the  main  object,  but  it  is  desirable  to 
give  them. 

NOTE 8   ON   PUMPS: 


Miscellaneous 
Belt  Transmission. 

HORSE  POWER  OF  SHAFTING. 


Diameter  of  Shaft 
in  Inches. 

REVOLUTIONS  PKR  MINUTE. 

100 

125 

150 

175 

200 

b.p. 

b.  p. 

b,  P. 

h.  p. 

b.p. 

15-16 

1.2 

1.4 

1.7 

2.1 

2.4 

1    3-16 

2.4 

3.1 

3.7 

4.3 

4.9 

1   7-16 

4.3 

5.3 

6.4 

7.4 

8  5 

1  11-16 

6.7 

8.4 

10.1 

11.7 

13.'4 

I  15-16 

io.a 

12.5 

16.0 

17-.  5' 

20.0 

2    3-16 

14.3 

17.8 

21.4 

24.9 

28  5 

2  .7-16 

19.5 

24.4 

29.3 

34.1 

39.0 

2  11-16 

26.0 

32.5 

39.0 

43.5 

52.0 

2  15-16 

33.8 

42.2 

,50.6 

59.1 

67.5 

3   3-16 

43.0 

53.6 

64.4 

75.1 

85  8 

3   7-16 
3  11-16 

53.6 
65.9 

67.0 
82.4 

79.4 
97.9 

93.8 
115.4 

107.2 
121.8 

315-16- 

80.0 

100.0 

120.0 

140.0 

160^0 

4    7-16 

113,9 

142.4 

170.  81 

199.8 

227.8 

4  15-16 

156!  3 

195.3 

234.4. 

273.4 

312.5 

HORSE  POWER  OF  BELTING. 

TABLE  FOR  SINGLE  LEATHER,  4-PLY  RUBBER  AND  4-pLT  COTTON 

BELTING,  BELTS  NOT  OVERLOADED.   (ONE  INCH  WIDE,  800 

FEET  PER  MINUTE  =  I-HORSE  POWER.) 


Speed  in  Ft. 


WIDTH  OP  BELTS  IN  INCHES. 


fer  Minute. 

2 

3 

4 

5 

6 

8 

10 

12- 

14 

16 

18 

20 

h.p 

h.p 

h.p 

h.p 

h.p 

h.p 

h.p 

h.p 

h.p 

hTp 

h.p. 

h.p." 

400 

1 

14 

2 

24 

3 

4 

5 

6 

7 

8 

9 

10 

600 

14 

44 

6 

74 

g 

104 

12 

134 

15 

800 

24 

3* 

4 

6* 

6^ 

8 

10 

12 

16 

18 

20 

1,000 
1,200 

2 
3 

3% 

5 

6 

6^ 

74 

3 

124 
15 

15 

18 

i 

20 
24 

1* 

25 
30 

1,500 
1,800- 

3% 
454 

5% 
6%, 

S* 

94 

114 

134 

15 

18 

18% 

224 

8* 

264 
314 

30 
36 

33% 
404 

45* 

2,000 

5 

10 

124 

15 

20 

25 

30 

35 

40 

45 

50 

2.400 

6 

9  * 

12 

15 

18 

24 

30 

36 

42 

48 

54 

60 

2,800 

7 

104 

14 

174 

21 

28 

35 

42 

49 

56 

63 

70 

3,000 

74 

11* 

15 

18% 

224 

30 

374 

45 

624 

60 

674 

75 

3,500 

8% 

13 

174 

26 

35 

44 

524 

61 

70 

79 

88 

4,000 

10 

15 

25 

30 

40 

50 

60 

70 

80 

90 

100 

4,500 

17 

224 

28 

34 

45 

57 

69 

78 

90 

102 

114 

5.000 

124 

19 

25 

31 

374 

50 

624 

75 

874 

100 

112 

125 

Double  leather,  6-ply  rubber  or  6-ply  cotton  belting  will  transmit 
50  to  75  per  cent,  more  power  than  is  shown  in  this  table. 

A  simple  rule  for  ascertaining  transmitting  power  of  belting, 
without  first  computing  speed  per  minute  that  it  travels,  is  as 
follows:  Multiply  diameter  of  pulley  in  inches  by  its  number  of 
revolutions  per  minute,  and  this  product  by  width  of  the  belt  in 
Inches  ;  divide  this  product  by  3,300  for  single  belting,  or  by  2,100 
for  double  belting,  and  the  quotient  will  be  the  amount  of  horse 
power  that  can  be  safely  transmitted. 


152   ELECTRICAL  AND  MECHANICAL  UNITS 
Equivalent  Values. 


COOLING  TOWERS. 


153 


Cooling  Towers. 

Cooling  towers  possess  operative  advantages  of  considerable  im- 
portance. There  is,  of  course,  a  certain  loss  of  water  by  evap- 
oration, but  this  rarely  exceeds  10  per  cent,  of  the  water  coooled, 
while  under  favorable  conditions  of  the  air  it  does  not  exceed 
5  per  cent. 

It  is  advisable  to  have  separate  towers  for  steam  condenser  and 
ammonia  condenser,  as  the  results  are  better  in  each  case.  The 
efficiency  of  the  cooling  tower  is  lowered  very  fast, '  when  the 
water  for  the  ammonia  condenser  is  much  above  80°,  whereas  for 
steam  condenser,  if  the  water  be  reduced  to  100°  the  tower  will 
be  fairly  efficient. 


FIG   55— FORCED  DRAFT  COOLING  TOWER. 


The    following   data    show   the    results    in    cooling   obtained    by 
the  use  of  cooling  towers: 

For  ammonia  condensers,  with  the  air  at  95°  F.  and  37  per  cent, 
humidity: 

Initial  temperature  of  water  entering  cooling  tower 100°  F. 

Final  temperature  of  water  leaving  cooling  tower 71°  F. 


Result   in   cooling   29°  F. 

For  steam  condensers,  with  the  air  at  95°  F.  and  44  per  cent, 
humidity: 

Initial  temperature  of  water  entering  cooling  tower 160°  F. 

Final  temperature  of  water  leaving  cooling  tower 81°  F. 

Result  in  cooling  79*  F. 

As  the  forced  draft  tower  seems  to  have  met  with  general  favor, 
we  append  a  few  tables,  stating  general  dimensions  and  capacity. 


154 


COOLING  TOWERS. 


Size  and  Weight  of  Goblin?  Towers. 


No,  of 

MAIN  DIMENSIONS. 

Weight 

Tower. 

A 

B 

C 

D      |       E 

f 

G 

H 

inlbi. 

I 

8'11J4* 

8'  654" 

J>  ft. 

9-  r- 

24'  9" 

22' 

18'11}4" 

19"  6/2" 

25,0(X> 

II 

91  954" 

6  ft. 

91  3" 

24'  9" 

32' 

191  954" 

19-11J4" 

28,500 

HI 

W  2YS 

9'95-r 

6  ft. 

9'10" 

24'  9" 

32* 

20*  2#" 

20'  9/a" 

32,000 

IV 

11'  5J4" 

10'  7J4" 

7  ft 

10'  4" 

24'  9" 

32* 

21'  554" 

22*  714' 

39,000 

V 

13'  354* 

12'  5}4" 

7  ft. 

11'  4* 

24,  9" 

23'  354" 

24'  554" 

46.000 

VI 

14'  6&." 

13'  354*' 

7  ft. 

12*  6" 

25'  8" 

32*  '9* 

24'  6H" 

25'  354" 

53,000 

VII 

16'  4&"I15'  1J4" 

7  ft. 

13'  4" 

25'  8" 

32'  9" 

26'  4^" 

27'  1-4" 

59,000 

VIII 

8  ft. 

14'  9» 

27'  4" 

34'  7* 

27'  7J4" 

29-454" 

65,700 

IX 

18'10J4"|17'  254" 

8  ft. 

15'  3"    1  2?'  4" 

34'  7" 

28'1(W" 

71.700 

•Cooling  Capacity  of  Cooline  Towers  and   Size  of  Fans. 


No.  of 
Tower 

Coding  Capacity 
la  Gallon*  lo 
84  houra  for: 

H.P.  of  comp. 
cond.  engine 
Supplied  with 
condens.  watef. 

|| 

1° 

08 

a 

M 

Size'of  Pulley. 

(Revol.  of  Pulley 
per  minute. 

M 

j> 

0. 

X 

Ammonia  1    Steam 
CONDENSERS 

'   I 
II 
III 
IV 
V 

& 
S" 

50,000 

.75,000 
100,000 
150.000 
200,000 
250,000 
300.000 
400.000 
500,000 

100.000 
150,000 
200.000 
300,000 
400.000 
500,000 
600.000 
800.000 

uxw.ooo 

50 
75 

100 
150 
200 
250 
300 
400 
500 

—  6ft 
—  6ft 
—  7ft 
—  8ft 
—  9ft 
—  10ft 
—10ft. 
-12ft. 
l-J2ft. 

15"x  8* 
15"x  8" 
18"x  9" 
24"x  9 
28"xlO" 
30"xll" 
30"xll" 
36"xir 
36"xl2" 

100—  1  25 
150—170 
140—150 
140—150 
130—140 
130—140 
145—150 
110—120 
140—150 

i  —  iy, 

V/2-2 
2    -2J4 
3J4—4  • 
•5-6 
7    -9 
10   —12 
13    —IS 
16    —20 

MISCELLANEOUS  NOTES: 


DOORS. 


155 


Doors 

Doors  are  a  weak  point  in  all  storage  rooms.  Their  Insulation 
is  important,  but  their  tightness  and  quick  operation  is 
vastly  more  so.  A  leak  is  an  endless  expense.  Slow  moving 
doors  are  hardly  less  so.  Doors  that  bind  and1  work  badly  are 
shut  only  when  the  workman  can  find  no  excuse  for  leaving  them 
open,  which  is  seldom,  if  ever.  , 

The  following  sketches  show  a  construction  which  is  patented, 
and  which  is  especially  contrived  to  avoid  these  troubles. 

The  door  makes  an  overlapping  contact,  with  a  soft  hemp  gasket 
in  the  joint,  and  is  held  to  its  seat  against  the  front  of  the  door 
frame  by  powerful  elas- 
tic hard*ware.  The 
thick  portion  of  the 
door  fits  loosely,  so 
that  considerable 
change  of  size,  form 
and  position,  due  to 
wear,  swelling,  etc., 
does  not  make  it  leak 
or  bind. 

Where  all  old  style 
doors,  when  they  work 
badly  or  leak,  must  be 
eased,  thus  forever  de- 
stroying their  fit,  a 
slight  readjustment  of 

the  door  frame  of  these  doors  restores  them   to  their  original  per- 
fection of  fit  and*  freedom  in  a  minute  at  no  expense. 

As   these  doors   do  not  stand   in   the   doorway   when   open,   it   can 
be  six  inches  less  in  width  than  old  style  doorways — an  important 
economy  in  refrigeration. 

As  constructed  in  this  year.  1908,  the  opening  in  wall 
to  receive  these  door  frames  should  be  3%  inches  wider, 
and  4  inches  higher,  than  the  size  of  the  doorway  in  the 
clear.  Follow  construction  numbered  1  and  2.  For  over- 
head1 track  doors  this  rough  opening  should  extend  13 
inches  above  the  lower  edge  of  track.  Door  frames  are 
secured  with  lag  screws,  %x4  inches,  through  front 

casing,  inserted  at  A. 
Figure  B  shows 
wooden  beveled  thres- 
hold, 1%  inches  thick, 
which  connects  lower- 
ends  of  door  frame  and 
JIPX  forms  a  part  of  it,  let 
down  into  floor.  No 
feather  edge,  no  jolt,  no  splinters.  For  warehouses.  Accommo- 
dates trucks. 

Figure  C,  cement  floor,  shows  lower  end's  of  door  frame  extend- 
ing down  into  the  door  a  distance  of  three  inches,  and  connected 
by  angle  irons  extending  across  doorway  from  one  side  to  the  other 
below  the  surface. 

Figure  S  shows  door  frame  with  full  standard  sill  and  head  used 
on  all  sizes  of  door  frames.  Suited!  only  to  walking  through. 

Special  doors  on  a  modified  plan  for  intermittent  or  continuous 
freezers,  as  well  as  for  general  purposes,  perfectly  tight  and  per- 
fectly free,  regardless  of  temperature,  moisture  or  accumulation  of 
ice  in  any  degree. 

Metal   covered   fireproof  doors. 

Combined  self-closing  ice  door  and  chute  of  three  styles. 
Ice   counters. 

Patents  on  every  valuable  feature  of  this  work  are  granted  to 
or  applied  for  by  the  STEVENSON  CO.,  CHESTER',  PA. 


156  ABSORPTION  MACHINES. 

Absorption  Machines. 

Since  going  to  press  the  author's  attention  has  been  called  to 
the  latest  design  of  the  Vogt  Absorption  Machine,  which  differs  in 
some  respects  from  the  one  given  on  page  23.  In  order  to  bring  the 
book  up  to  date  the  following  brief  description  is  here  appended  : 

The  strong  liquor  is  drawn  from  the  absorber  and  pumped  into 
the  upper  end  of  the  rectifier  and1  passes  down  through  the  small 
pipes  and  out  from  the  bottom  of  rectifier  to  the  bottom  pipes  of 
the  exchanger,  where  it  passes  upward  through  the  inner  pipes 
and  out  from  the  top  of  exchanger  to  top  of  analyzer,  where  the 
liquid  falls  in  a  spray  from  one  pan  to  another  until  it  reaches 
the  top  compartment  of  the  generator. 

The  gas  generated  passes  upward  in  the  analyzer  and  is  cooled 
and  deprived  of  a  portion  of  its  moisture  by  coming  in  contact 
with  the  liquid  trickling  down  from  pan  to  pan  in  the  analyzer. 
The  gas  passes  on  and  enters  the  rectifier  at  bottom  and'  completely 
surrounds  the  tubes  through  which  the  rich  aqua  is  flowing,  and  as 


VOGT    ABSORPTION    MACHINE. 

the  rich  aqua  is  comparatively  cool  as  against  the  gas,  the  moisture 
in  the  gas  will  condense  and  deposit  itself  on  the  tubes  as  the  gas 
is  forced  upward,  allowing  the  gas  to  pass  over  dry  to  the  con- 
denser. The  moisture  withdrawn  and  adhering  to  the  tubes  will 
drain  out  at  the  bottom  of  the  rectifier  and  back  into  the  top  com- 
partment of  the  generator. 

The  gas  from  the  rectifier  is  ad'mitted  to  the  top  of  the  con- 
densing coils,  where  it  quickly  liquefies  and  is  conducted  from  the 
bottom  of  the  condenser  to  the  liquid  ammonia  receiver. 

The  weak  liquid  having  in  the  meantime  passed  from  bottom  of 
generator  to  top  of  exchanger,  and  down  through  the  outer  pipes 
of  same,  is  conducted  to  the  weak  liquid  cooler  to  be  further  re- 
duced1 in  temperature,  and  is  finally  conducted  to  the  absorber, 
•where  the  gas  from  the  refrigerating  coils  is  rapidly  absorbed,  and 
the  double  cycle  of  circulation  is  thus  completed. 


REFRIGERATING    ENGINEERS3    POCKET    MANUAL. 


GREAT  Ml  HE1G 

DETROIT,  MICHIGAN 

We  have  the  EQUIPMENT  and  the  ORGAN- 
IZATION  for  successfully  building  and  install- 
ing  "ECONOMICAL"  ICE  MAKING  and  RE- 
FRIGERATING PLANTS. 


._*- 

25  TO  50  TON  REFRIGERATING  MACHINE 

"GREAT  LAKES  MACHINES"  have  Sym- 
metrical Proportions  and  present  a  NEAT  and 
ATTRACTIVE  APPEARANCE. 


YOU  GET  RESULTS  FROM 
OUR  PLANTS. 


WRITE  \/S  TO'R  TA.'RTICVLA.'RS' 


NOTES 


NOTES. 


NOTES. 


NOTES  . 


NOTES. 


NOTES. 


NOTES. 


NOTES. 


NOTES. 


NOTES. 


NOTES. 


NO  TES. 


NOTES. 


REFRIGERATING    ENGINEERS'    POCKET   MANUAL. 


The  Linde  Machine 

FOR  ALL 

ICE  AND  REFRIGERATING 
SERVICE 

Simple,  Durable,  Economical 

Best  advertised  by  the 
number  of  its  pleased  users 

...     6500 

Throughout  the  World 

Ammonia'  Fittings,  Pipe 
and  Tank  Work;  Ice  and 
Refrigerating  Supplies. 

CATALOGS  GLADLY  SENT  ON  REQL7EST 

The  Fred  W.  Wolf  Company 

(Established  1867) 

Main  Office  and  Works,  139-143  Rees  St.,  Chicago 

Atlanta  Kansas  City  Port  Worth  Seattle 


REFRIGERATING    EXCIXEERS'    POCKET    MAXUAL. 


ABSORPTION 

Ice  and  Refrigerating 
Machinery 


HENRY  VOdl  MACHINE  (0. 

Incorporated 

LOUISVILLE,  KY.,  U.S.A. 

AsK  for  Catalog' 


REFRIGERATING    ENGINEERS'    POCKET    MANUAL. 


The  National  Ammonia  Co. 

MainOificej  .-  ,  ,  ,  ST,  LOUIS 
Eastern  Office  *  .  .  ,  PHILADELPHIA 
Export  Office  j  30  PI att  Street,  NEW  YORK 

Factories :  St.  Louis  and  Philadelphia 


AND 


Peerless  Aqua 
Ammonia,  26 c 


Tlese  Ufdofc  (jive  Ifloy,  (s^ 

-NATIONAL  ORIGINALITY:" 

Standard  of  quality  for  over  30  years, 

Prompt  shipments  or  deliveries, 

Ammonia  manufacture  our  exclusive  business. 

Quality  guarantee  full  and  unreserved. 

A  guarantee  that  is  reliable  and  responsible, 

(For  list  of  stocks  see  current  trade  papers) 


REFRIGERATING    ENGINEERS'    POCKET    MANUAL. 


AUTOMATIC 
REFRIGERATION 


Our  Automatic  Systems  furnish  Re- 
frigeration at  a  lower  operating  cost 
than  any  other  system  on  the  market. 

THE  AUTOMATIC  REFRIGERATING  CO. 

HARTFORD,    CONN 


REFRIGERATING    ENGINEERS'    POCKET    MANUAL. 


HART 

•*  SECTIONAL 

COOLING 
TOWER 


(PATENTS  PENDING.) 

A  new  form  of  water 
cooling  apparatus  where 
the  cooling  surface  is  made 
up  of  sections  arranged  so 
that  the  cooling  air  cur- 
rents are  brought  in  con- 
tact with  the  interior  por- 
tions of  the  falling  water, 
thus  creating  an  increased 
efficiency  over  present 
types.  The  heated  water 
is  discharged  to  the  top  of 
.  the  tower,  where  it  is  dis- 
tributed through  a  special 
device  to  the  upper  deck  of 
Cooling  Trays,  from  whence 
it  falls  by  gravity  from 

dock  to  deck,   and  its  descent  is  turned  over  and  over,   reaching  the 
collecting  pan  at  the  bottom,  cooled,  and  ready  for  use  again. 

YOU  are  not  getting  the  best  results  have  Hart  Sectional 
Cooling  Trays  placed  in  your  tower  and  get  them. 

YOUR  tower  is  too  small,  let  us  increase  its  capacity  at  a 
low  cost. 

YOU  have  spray  troubles,  Hart  Adjustable  Spray  Preventer 
will  cure  them. 

With   the  use  of  the  Hart   Spray  Preventer,    there  is  no  loss  of 
water  beyond  that  due  to  evaporation. 


If 


H 


AVE  YOU  A  COOLING  PROBLEM? 


ARE     YOU     SATISFIED     WITH     YOUR     PRESENT 
COOLING    FACILITIES? 
D  ESULTS  TELL  OUR  STORY. 

TFE    COST    IS    SMALL    WHEN    COMPARED    WITH 
THE   SAVING. 

The  above  applies  to  Steam  Power  Plants,  Breweries,  Ice  and 
Refrigeration  Plants.  Gas  Engine' Plants,  Packing  Houses  and  all 
industries  where  cold  water  is  required. 


Oi 


MTJR 
RIGINAL 
FFER. 


B.  FRANKLIN  HART,   JR.,    £&  CO. 

Main  Office:   143  Liberty  St.,   New  York  City. 

Branches:  Morris  &  Co.,  Dallas,  Texas, 

Walter  A.  Taylor,  New  Orleans,  La. 


REFRIGERATING    ENGINEERS'    POCKET    MANUAL. 


THE  SAFETY  REFRIGERATING  MACHINE 


Established  1872  Manutactured  by  Incorporated  1894 

THE    HUETTEMAN  &  CRAMER  CO. 

Refrigerating    and    Brewers'    Machinery 

Office  and  Works  Contractor*  for  Hntire  Plant 

Mack  Ave.  &  Beit  Line  R.  R.t  Detroit,  Mich 


Buffalo    Refrigerating   Machine    Co. 

Manufacturers  of 

REFRIGERATING  AND 
ICE  MACHINERY 


126  Liberty  Street, 


NEW  YORK 


REFRIGERATING    ENGINEERS'    POCKET    MANUAL. 


Remington 
Machine  Company 

WILMINGTON,  DELAWARE 


Ice  Making 
and 

Refrigerating 
Machines 


-  The  Remington 
Ice  Machine  is  the 
Standard  Machine 
of  small  capacity. 


VORHEES'    PATENTED 
SPECIALTIES 

SHELL  TYPE  BRINE  COOLERS 
DOUBLE  PIPE  APPARATUS 
MULTIPLE  EFFECT  COMPRESSORS 
GAS  TRAPS 
OIL  SEPARATORS 
AIR  COOLERS 

AUTOMATIC  GAUGE  COCKS 
ICE  FREEZING  APPARATUS 

GARDNER    T.   VOORHEES 
53  STATE  ST.  BOSTON,  MASS. 


REFRIGERATIXG    EXGIXEERS'    POCKET    MANUAL. 


REFRIGERATING    ENGINEERS'    POCKET   MANUAL. 


Cold  Storage, 
Warehouse  and 

Power  House 
Containing 

Refrigerating 

Machinery  for 

Warehouse, 

Ice  Making 

and  Street 

Pipe  Line 

Installed  at 

Murphy 

Storage  & 

Ice  Co. 

Detroit,  Mich. 


BY 


STARR  ENGINEERING  CO. 


JOHN  E.  STARR,  Pres't 


KARL  WEQEMANN,  Sec'y 


Consulting   and    Supervising 
Engineers   and   Architects 

Complete  Cold  Storage  Plants, 

Ice  Plants,  Abattoirs, 

Street  Pipe  Lines,  Tests, 

Expert  Advice  and  Testimony. 

Hudson  Terminal  Bldg.  50  Church  St. 

NEW  YORK,  N.  Y. 


REFRIGERATING    ENGINEERS'    POCKET    MANUAL 


Theo.  Kolischer 
Engineering  Bureau 

SPECIALISTS    IN    MECHANICAL 
REFRIGERATION 

20   Years'  Experience   in  All  Its   Applications 

Members   American    Society    of 
Refrigerating  Engineers 

CONSULTATION.        SPECIFICATIONS 

AND  PLANS  PREPARED.    SUPERVISION 

EXERCISED  DURING  INSTALLATION 

1 218  Chestnut  St.,   PHILADELPHIA 


COLD  STORAGE 

Construction  Plans,  Specifications  and 
Estimates  Furnished 


We  use  up-to-date  methods 
and  give  results. 

Hot  and  Cold  Pipe  Covering 


JOHN  R.  LIVEZEY 

1933  Market  Street,  PHILADELPHIA,  PA, 


REFRIGERATING    ENGINEERS3    POCKET   MANUAL. 

WATER  EXPERT 

I  Analyses  of  water  for  ice-making  purposes, 

condenser  water,  oils  and  other  materials 
used  in  refrigerating  systems. 
JOHN  C  SPARKS,  B.  Su  F.  C  S. 

Consulting  and  Analytical  Chemist 

No.  16  BEAVER  STREET,  NEW  YORK 


EDWARD  N+  FRIEDMANN 

CONSULTING  AND  SUPERVISING  ENGINEER 

for  all  applications  of  mechanical  refrigeration 
90  WEST  STREET,  NEW  YORK  CITY 


Mcmbor   American    Society   of   Refrigerating   Engineers. 


AMMONIA          AMMONIA  FITTINGS          CALCIUM 

T.    R.  WINGROVE 

Refrigerating  6ngsneer 

ICE  MAKING  AND  REFRIGERATING  MACHINERY 

65  Gunther  Building 

C.  &  P.  Phone,  St.  Paul  3955  BALTIMORE,   MD. 


WALDEMAR  H.  MORTENSEN,  C.  E.  GUSTAVE  F.    GEIBELT. 

ADOLPH  G.  KOENIG,   M.   E. 

MORTENSEN  &  CO. 
Engineers  and  Contractors 

401   W.  24th  Street,  NEW  YORK 

Designers  and  Contractors  of 

Breweries,   Abattoirs,    Ice   Factories,   Power  Plants  and 
Manufacturing  Building's  in  General 


REFRIGERATING    ENGINEERS'    POCKET   MANUAL. 


W.  EVERETT  PARSONS,  M.E. 

CONSULTING  ENGINEER 

Expert  in  Ice  Making  and  Refrigeration  and 
Business  Management  of  Ice  Plants 


Plans    for    Refrigerating    and    Ice    Making    Plants, 

Existing  Plants    Remodeled  and    Improved, 

Operating  Expenses  Reduced 


Graduate  of  Stevens  Institute  of  Technology,   1887 

Member:    Am.    Soc.    Refrig.    Engineers. 
Am.    Soc.    Mech.    Engineers. 
Cold    Storage    &    Ice    Association   of  London,    Eng. 

18  Years  Experience  as  a  Specialist 

12  Bridge  St.,      -      -      NEW  YORK  CITY 


GARDNER  L  VOORHEES,  S.  B. 

Refrigerating  engineer 
and  Hrcbiteet    /    /    / 

Graduate    of   Massachusetts    Institute    of   Technology    1890. 
Member   Am.    Soc.    Ref.    Engs. 
Member  Am.    Soc.   Mech.    Engs. 

MECHANICAL  REFRIGERATION 

in  all  its  applications  as  Compression  Plants,  Absorption  Plants, 
Cold  Storage  Warehouses.  Ice  Plants,  Street  Pipe  Line  Refri- 
geration, Breweries,  Cooling  Rooms  or  building  for  comfort  of 
man.  Skating  Rinks,  etc.,  etc. 

EXPERT  WORK,  TEST,  REPORTS, 
APPRAISING,  ETC, 

53  STATE  ST.  BOSTON,  MASS. 


REFRIGERATING    ENGINEERS'    POCKET   MANUAL. 


Empire  State  Engineering  Company 


ENGINEERS 
MANUFACTURERS 


Builders  of 

Empire  State 
Refrigerating   Machines 

Leyland  Automatic  Lubricator,  Maxfield 
Steam  Engines,  Fans,  Blowers,   Etc. 

CATALOGUES  MAILED  ON  APPLICATION 

General  Offices:  Singer  Bldg.,  N.Y.  City,  N.Y. 

Works:  ROME, M.  Y. 


REFRIGERATING    ENGINEERS'    POCKET    MANUAL. 


GUARANTEED 

Strictly  Wrought  Iron  Pipe 


FOR 


Refrigeration 
Apparatus, 
Pipe  Bends 
and 

Coils        Iff  Valves, 

Fittings 
««i  Supplies 
for  Steam, 
Water,  Gas,  Oil 


OFFICES   and   SHOPS 

446  to  454  Water  Street 
187-189  Cherry  Street 
NEW  YORK 


REFRIGERATING    ENGIN  KIMS'    POCKET    MANUAL. 


THE   WHITLOCH   COIL   PIPE  CO. 

MANUFACTURERS    OF 

WROUGHT    IRON   AMMONIA 

COILS 

OF     EVERY     DESCRIPTION 

ALSO 

BENT    and    FLANGED    PIPE 

FOR 

HIGH  PRESSURE  POWER  PLANTS 

THE    WHITLOCK     COIL     PIPE     CO. 

Hartford,    Conn. 

New  York  Office:    Singer  Building 


ESTABLISHED    i860 

T.  R.  McMannCo. 

Wrought  Pipe,  Plumbers 


and 


Engineers*  Supplies 

Pipe  Cut  to  Sketch 

56-58-60    GOLD     STREET 

New   YorK   City 


REFRIGERATING    ENGINEERS'    POCKET   MANUAL. 

LILLIE  EVAPORATORS 

Single  and  Multiple  Effects 

For  the  production  of 

DISTILLED  WATER 
for  Ice  Making  Plants  and  other  purposes. 

The  Lillie  Evaporators  are  used  for  the  production 
of  distilled  water  in  many  ice  plants,  in  connection 
with  compound  condensing  engines,  taking  the 
steam  from  the  latter  under  a  pressure  of  about 
sixteen  inches  vacuum. 


A  Lillie  1904-1905  Model  Triple-Effect  distiller 
with  surface  condenser  in  the  works  of  the  Con- 
sumers' Ice  and  Cold  Storage  Company,  Key 
West,  Fla.  It  is  employed  in  manufacturing  dis- 
tilled water  from  sea  water.  In  this  triple-effect  is 
embodied  a  patented  construction  for  reversing  the 
direction  of  the  vapors,  which  has  proven  very  suc- 
cessful in  keeping  down  incrustations. 

The  Sugar  Apparatus   Mfg.  Co. 

S.  MORRIS  LILLIE.  President  Makers        LEWIS  C.  LILLIK.  Sec'y-Treas. 

Philadelphia,  U.  S.  A. 


REFRIGERATING'  ENGINEERS'    POCKET   MANUAL. 


The  Linde  British 
Refrigeration  Co.,  Ltd. 

of   Canada 
Coristine  Building  MONTREAL,  P.  Q, 


Manufacturers  of 

Refrigerating 


and 


Ice  Making 
Machinery 


For  All  Purposes 


Sole  Manufacturers  of  the 

LINDE    PATENT   DRY    AIR 
CIRCULATION   SYSTEM 


SHIPS    REFRIGERATION 
A  SPECIALTY 


The  American  Linde 

Refrigeration  Co.,  Ltd. 

346  BROADWAY  NEW  YORK 


REFRIGERATING    ENGINEERS'   POCKET   MANUAL. 


Ice  and  Refrigerating  Machinery 

1  TO  100  TONS 

Vertical   and   Horizontal  Compressors 

Double  Pipe  Condensers  and 

Brine  Coolers 

Carbonic  System 

Efficient,  Odorless,  Safe,  Economical 
Lowest  Temperatures 

LAND  AND  MARINE 
INSTALLATIONS  COMPLETE 


THE  BROWN  -  COCHRAN  Co. 

LORAINE,  OHIO 


REFRIGERATING    ENGINEERS'    POCKET    MANUAL. 


THE  IMPROVED  BARBER 

Refrigerating  and  Ice  Making  Machines 


build  refrigerating  machines  for  all 
purposes  and  in  all  sizes  from.l^ 
tons  to  500  tons  capacity.  We  have 
over  1,400  machines  in  successful  operation 
Jan.  1,  1908.  Our  machines  can  be  used 
with  any  kind  of  power,  the  smaller  sizes 
being  especially  designed  for  belt  drive. 

The  above  cut  represents  our  horizontal, 
double-acting  compressor,  connected  tan- 
dem, which  we  build  in  sizes  of  30  tons  and 
upward.  It  has  fewer  parts,  fewer  bearings 
and  runs  with  less  power,  less  oil  and  less 
attendance,  and  is  consequently  more  eco- 
nomical. 

C.  P.  M.  Co.  Ammonia  Fittings  are  stand- 
ard. Specify  them  in  your  next  order  for 
repairs. 

Write  for  catalogues,  estimates  or  any  de- 
sired information. 


CREAMERY   PACKAGE    MFG.    COMPANY 

Refrigerating  Machinery  Department 
182-188  KINZIE  STREET,  CHICAGO,  ILLINOIS 

Works,  DeKalb,  Ills. 


REFRIGERATING    ENGINEERS'    POCKET    MANUAL 


Horizontal  Machine. 


Air  at  about 
65  Ibs.  pres- 
sure, circula- 
ting in  com- 
mon smallcon- 
veying  and 
refrigerating 
pipes,  is  refri- 
gerated by  the 
machine  to  33° 
below  zero 
when  the  sea- 
water  is  at  90°. 
There  are  no 
auxiliary  parts 

outside  of  the  machine.      It  is  placed  in  the  engine    room,    ice- 
making    box    and  meat-room  forward  as  usual. 

HALF  TON  VERTICAL   (3'-6n  x  3')    furnishes   ice   and 

refrigerates   meat-rooms,   etc.,    for    steam    yachts    of    200    feet 

length,  including  "  Kanawha." 

ONE  TON  VERTICAL  (41  x  V)  or  Horizontal  (7'  x  3'- 

6")  for  steam  yachts  250'  length,    including  "  Nourmahal "  and 

"Atalanta." 

TWO    TON    VERTICAL    (5'  x  5').  or  Horizontal  (9'  x 

4' -6")  for  larger  yachts,  including  "Josephine." 

15he  Allen  Dense 
Air  Ice  Machine 


uses  no  chemicals,  only  air. 
It  refrigerates  the  meat-stores 
and  furnishes  the  ice  and 
cold  drinking  water  on  all 
large  U.  Sr  Men-of-War, 
since  many  years. 


H.  B.  ROEEKER 

41  Maiden  Lane 
NEW  YORK 


Vertical    Machine. 


REFRIGERATING    ENGINEERS'    POCKET   MANUAL. 


THE  ARCTIC  ICE 
MACHINE  CO. 


The  name  ARCTIC  as  applied  to  Ice  Making  and 
Refrigerating  equipment  stands  for 

QUALITY 

SIMPLICITY,  DURABILITY  and  EFFICIENCY 

as  embodied  in  apparatus  of  our  manufacture  brings 

BEST    RESULTS 

ARCTIC  USERS  are  our  best  FRIENDS 

The  Arctic  Ice  Machine  Go. 

Write  us.  CANTON,    OHIO 


14  DAY  USE 

RETURN  TO  DESK  FROM  WHICH  BORROWED 

LOAN  DEPT. 

This  book  is  due  on  the  last  date  stamped  below,  or 

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